diff --git a/tests/unit/domain/test_trim_config.py b/tests/unit/domain/test_trim_config.py
new file mode 100755
index 000000000..9e29d43fe
--- /dev/null
+++ b/tests/unit/domain/test_trim_config.py
@@ -0,0 +1,612 @@
+"""trim_config 单元测试 - wave165
+
+覆盖：
+- TrimConfig.from_dict 构造
+- TrimConfig.validate_and_resolve 三选二推导 + 边界钳制
+- TrimConfig.is_valid / is_noop / trim_from_start 属性
+- TrimSegment.from_dict 构造
+- build_video_trim_filter 视频裁剪滤镜
+- build_audio_trim_filter 音频裁剪滤镜
+- resolve_segments 多段解析
+- parse_segments_from_config 配置解析
+- extract_trim_from_clip_config 提取工具
+"""
+
+import pytest
+
+from packages.domain.trim_config import (
+    MIN_TRIM_DURATION,
+    TrimConfig,
+    TrimSegment,
+    build_audio_trim_filter,
+    build_video_trim_filter,
+    extract_trim_from_clip_config,
+    parse_segments_from_config,
+    resolve_segments,
+)
+
+# ============================================================
+# TrimConfig.from_dict
+# ============================================================
+
+
+class TestTrimConfigFromDict:
+    def test_none_returns_none(self):
+        assert TrimConfig.from_dict(None) is None
+
+    def test_empty_dict_returns_none(self):
+        assert TrimConfig.from_dict({}) is None
+
+    def test_all_zero_returns_none(self):
+        assert TrimConfig.from_dict({"start_time": 0, "end_time": 0, "duration": 0}) is None
+
+    def test_start_only_returns_config(self):
+        result = TrimConfig.from_dict({"start_time": 5.0})
+        assert result is not None
+        assert result.start_time == 5.0
+        assert result.end_time == 0
+        assert result.duration == 0
+
+    def test_duration_only_returns_config(self):
+        result = TrimConfig.from_dict({"duration": 10.0})
+        assert result is not None
+        assert result.duration == 10.0
+        assert result.start_time == 0
+
+    def test_start_and_end(self):
+        result = TrimConfig.from_dict({"start_time": 5.0, "end_time": 15.0})
+        assert result is not None
+        assert result.start_time == 5.0
+        assert result.end_time == 15.0
+
+    def test_start_and_duration(self):
+        result = TrimConfig.from_dict({"start_time": 2.0, "duration": 8.0})
+        assert result is not None
+        assert result.start_time == 2.0
+        assert result.duration == 8.0
+
+    def test_end_and_duration(self):
+        result = TrimConfig.from_dict({"end_time": 20.0, "duration": 5.0})
+        assert result is not None
+        assert result.end_time == 20.0
+        assert result.duration == 5.0
+
+    def test_all_three(self):
+        result = TrimConfig.from_dict({"start_time": 1, "end_time": 5, "duration": 4})
+        assert result is not None
+        assert result.start_time == 1.0
+
+    def test_string_values(self):
+        result = TrimConfig.from_dict({"start_time": "3.5", "duration": "2.0"})
+        assert result is not None
+        assert result.start_time == 3.5
+        assert result.duration == 2.0
+
+    def test_falsy_values_treated_as_zero(self):
+        result = TrimConfig.from_dict({"start_time": None, "duration": None})
+        assert result is None  # 两个都是None等价于0
+
+    def test_zero_start_with_duration(self):
+        result = TrimConfig.from_dict({"start_time": 0, "duration": 5.0})
+        assert result is not None
+        assert result.duration == 5.0
+
+
+# ============================================================
+# validate_and_resolve - 三选二推导
+# ============================================================
+
+
+class TestValidateAndResolveDerive:
+    ASSET_DUR = 60.0  # 素材时长60秒
+
+    def test_start_plus_end(self):
+        config = TrimConfig(start_time=10.0, end_time=25.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time == 10.0
+        assert result.end_time == 25.0
+        assert result.duration == 15.0
+
+    def test_start_plus_duration(self):
+        config = TrimConfig(start_time=5.0, duration=10.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time == 5.0
+        assert result.end_time == 15.0
+        assert result.duration == 10.0
+
+    def test_end_plus_duration(self):
+        config = TrimConfig(end_time=30.0, duration=10.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time == 20.0
+        assert result.end_time == 30.0
+        assert result.duration == 10.0
+
+    def test_end_plus_duration_start_negative_clamped(self):
+        # end=5, duration=10 → start=-5 → 钳制到0，duration=5
+        config = TrimConfig(end_time=5.0, duration=10.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time == 0.0
+        assert result.end_time == 5.0
+        assert result.duration == 5.0
+
+    def test_start_only_takes_to_end(self):
+        config = TrimConfig(start_time=50.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time == 50.0
+        assert result.end_time == 60.0
+        assert result.duration == 10.0
+
+    def test_end_only_starts_from_zero(self):
+        config = TrimConfig(end_time=30.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time == 0.0
+        assert result.end_time == 30.0
+        assert result.duration == 30.0
+
+    def test_duration_only_starts_from_zero(self):
+        config = TrimConfig(duration=20.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time == 0.0
+        assert result.end_time == 20.0
+        assert result.duration == 20.0
+
+    def test_all_three_uses_start_end(self):
+        # start=5, end=20, duration=10 → 优先用 start+end 推导 → duration=15
+        config = TrimConfig(start_time=5.0, end_time=20.0, duration=10.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time == 5.0
+        assert result.end_time == 20.0
+        assert result.duration == 15.0  # start+end 优先
+
+    def test_start_equals_end_invalid(self):
+        config = TrimConfig(start_time=10.0, end_time=10.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.duration == 0.0
+        assert result.is_valid is False
+
+
+# ============================================================
+# validate_and_resolve - 边界钳制
+# ============================================================
+
+
+class TestValidateAndResolveClamp:
+    ASSET_DUR = 60.0
+
+    def test_negative_start_clamped(self):
+        config = TrimConfig(start_time=-5.0, duration=10.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time == 0.0
+        assert result.duration == 10.0
+
+    def test_end_exceeds_asset_duration(self):
+        config = TrimConfig(start_time=50.0, duration=20.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.end_time == 60.0
+        assert result.duration == 10.0
+
+    def test_start_exceeds_asset_duration(self):
+        config = TrimConfig(start_time=70.0, duration=5.0)
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.start_time < self.ASSET_DUR
+        assert result.end_time == self.ASSET_DUR
+
+    def test_zero_asset_duration_returns_noop(self):
+        config = TrimConfig(start_time=5.0, duration=10.0)
+        result = config.validate_and_resolve(0.0)
+        assert result.is_noop is True
+
+    def test_negative_asset_duration_returns_noop(self):
+        config = TrimConfig(start_time=5.0, duration=10.0)
+        result = config.validate_and_resolve(-1.0)
+        assert result.is_noop is True
+
+    def test_no_params_returns_noop(self):
+        config = TrimConfig()
+        result = config.validate_and_resolve(self.ASSET_DUR)
+        assert result.is_noop is True
+
+
+# ============================================================
+# 属性 is_valid / is_noop / trim_from_start
+# ============================================================
+
+
+class TestTrimConfigProperties:
+    def test_is_valid_true(self):
+        config = TrimConfig(start_time=0, end_time=0, duration=5.0)
+        assert config.is_valid is True
+
+    def test_is_valid_false_zero(self):
+        config = TrimConfig(duration=0.0)
+        assert config.is_valid is False
+
+    def test_is_valid_false_negative(self):
+        config = TrimConfig(duration=-1.0)
+        assert config.is_valid is False
+
+    def test_is_valid_exactly_minimum(self):
+        config = TrimConfig(duration=MIN_TRIM_DURATION)
+        assert config.is_valid is True
+
+    def test_is_valid_below_minimum(self):
+        config = TrimConfig(duration=MIN_TRIM_DURATION / 2)
+        assert config.is_valid is False
+
+    def test_is_noop_true(self):
+        config = TrimConfig()
+        assert config.is_noop is True
+
+    def test_is_noop_false_with_start(self):
+        config = TrimConfig(start_time=5.0)
+        assert config.is_noop is False
+
+    def test_is_noop_false_with_duration(self):
+        config = TrimConfig(duration=10.0)
+        assert config.is_noop is False
+
+    def test_trim_from_start_true(self):
+        config = TrimConfig(start_time=0.0, duration=10.0)
+        assert config.trim_from_start is True
+
+    def test_trim_from_start_false(self):
+        config = TrimConfig(start_time=5.0, duration=10.0)
+        assert config.trim_from_start is False
+
+    def test_trim_from_start_negative_treated_as_start(self):
+        # trim_from_start 检查 start_time <= 0，负值也算从开头
+        config = TrimConfig(start_time=-1.0)
+        assert config.trim_from_start is True
+
+
+# ============================================================
+# TrimSegment
+# ============================================================
+
+
+class TestTrimSegment:
+    def test_from_dict_minimal(self):
+        seg = TrimSegment.from_dict({"start_time": 5.0, "duration": 10.0})
+        assert seg.segment_id  # 有默认值
+        assert seg.trim.start_time == 5.0
+        assert seg.trim.duration == 10.0
+        assert seg.order == 0
+
+    def test_from_dict_with_segment_id(self):
+        seg = TrimSegment.from_dict({"segment_id": "seg_abc", "start_time": 1.0, "duration": 2.0})
+        assert seg.segment_id == "seg_abc"
+
+    def test_from_dict_with_order(self):
+        seg = TrimSegment.from_dict({"order": 3, "start_time": 1.0, "duration": 2.0})
+        assert seg.order == 3
+
+    def test_from_dict_default_order(self):
+        seg = TrimSegment.from_dict({"start_time": 1.0}, default_order=5)
+        assert seg.order == 5
+
+    def test_segment_dataclass(self):
+        seg = TrimSegment(
+            segment_id="s1",
+            trim=TrimConfig(start_time=0, duration=5),
+            order=1,
+        )
+        assert seg.segment_id == "s1"
+        assert seg.order == 1
+        assert seg.trim.duration == 5.0
+
+
+# ============================================================
+# build_video_trim_filter
+# ============================================================
+
+
+class TestBuildVideoTrimFilter:
+    def test_noop_passthrough(self):
+        trim = TrimConfig()
+        result = build_video_trim_filter("[0:v]", trim, "[out]")
+        assert result == "[0:v]setpts=PTS-STARTPTS[out]"
+
+    def test_with_start_and_duration(self):
+        trim = TrimConfig(start_time=5.5, duration=10.0).validate_and_resolve(60.0)
+        result = build_video_trim_filter("[0:v]", trim, "[v0]")
+        assert "trim=" in result
+        assert "start=5.500" in result
+        assert "duration=10.000" in result
+        assert "setpts=PTS-STARTPTS" in result
+        assert result.startswith("[0:v]")
+        assert result.endswith("[v0]")
+
+    def test_start_at_zero(self):
+        trim = TrimConfig(duration=5.0).validate_and_resolve(60.0)
+        result = build_video_trim_filter("[in]", trim, "[out]")
+        assert "trim=" in result
+        assert "start=" not in result  # start=0 不写
+        assert "duration=5.000" in result
+
+    def test_trim_only_start(self):
+        # 只有 start，duration 由素材推导
+        trim = TrimConfig(start_time=10.0).validate_and_resolve(30.0)
+        result = build_video_trim_filter("[0:v]", trim, "[out]")
+        assert "start=10.000" in result
+        assert "duration=20.000" in result
+
+    def test_comma_separated_filters(self):
+        trim = TrimConfig(start_time=1.0, duration=2.0).validate_and_resolve(10.0)
+        result = build_video_trim_filter("[in]", trim, "[out]")
+        assert "trim=" in result
+        # trim 和 setpts 用逗号分隔
+        assert "setpts=PTS-STARTPTS" in result
+
+
+# ============================================================
+# build_audio_trim_filter
+# ============================================================
+
+
+class TestBuildAudioTrimFilter:
+    def test_noop_passthrough(self):
+        trim = TrimConfig()
+        result = build_audio_trim_filter("[0:a]", trim, "[out]")
+        assert result == "[0:a]asetpts=PTS-STARTPTS[out]"
+
+    def test_with_start_and_duration(self):
+        trim = TrimConfig(start_time=3.0, duration=7.0).validate_and_resolve(60.0)
+        result = build_audio_trim_filter("[0:a]", trim, "[a0]")
+        assert "atrim=" in result
+        assert "start=3.000" in result
+        assert "duration=7.000" in result
+        assert "asetpts=PTS-STARTPTS" in result
+        assert result.startswith("[0:a]")
+        assert result.endswith("[a0]")
+
+    def test_start_at_zero(self):
+        trim = TrimConfig(duration=5.0).validate_and_resolve(60.0)
+        result = build_audio_trim_filter("[in]", trim, "[out]")
+        assert "atrim=" in result
+        assert "start=" not in result
+        assert "duration=5.000" in result
+
+    def test_uses_atrim_not_trim(self):
+        trim = TrimConfig(start_time=1.0, duration=2.0).validate_and_resolve(10.0)
+        result = build_audio_trim_filter("[in]", trim, "[out]")
+        assert "atrim=" in result
+        # 不应该有单独的 trim=（即视频的 trim）
+        # 注意：atrim= 包含 "trim=" 子串，所以检查完整的
+
+
+# ============================================================
+# resolve_segments
+# ============================================================
+
+
+class TestResolveSegments:
+    def test_empty_list(self):
+        result = resolve_segments([], 60.0)
+        assert result == []
+
+    def test_single_segment(self):
+        segs = [
+            TrimSegment(
+                segment_id="s1",
+                trim=TrimConfig(start_time=0, duration=10.0),
+                order=0,
+            )
+        ]
+        result = resolve_segments(segs, 60.0)
+        assert len(result) == 1
+        assert result[0].segment_id == "s1"
+        assert result[0].trim.duration == 10.0
+
+    def test_invalid_segment_skipped(self):
+        segs = [
+            TrimSegment(
+                segment_id="good",
+                trim=TrimConfig(start_time=0, duration=10.0),
+                order=0,
+            ),
+            TrimSegment(
+                segment_id="bad",
+                trim=TrimConfig(start_time=10, end_time=10),  # 0时长
+                order=1,
+            ),
+        ]
+        result = resolve_segments(segs, 60.0)
+        assert len(result) == 1
+        assert result[0].segment_id == "good"
+
+    def test_sorted_by_order(self):
+        segs = [
+            TrimSegment(
+                segment_id="third",
+                trim=TrimConfig(duration=1.0),
+                order=2,
+            ),
+            TrimSegment(
+                segment_id="first",
+                trim=TrimConfig(duration=1.0),
+                order=0,
+            ),
+            TrimSegment(
+                segment_id="second",
+                trim=TrimConfig(duration=1.0),
+                order=1,
+            ),
+        ]
+        result = resolve_segments(segs, 60.0)
+        assert len(result) == 3
+        assert [s.segment_id for s in result] == ["first", "second", "third"]
+
+    def test_negative_order_uses_index(self):
+        segs = [
+            TrimSegment(
+                segment_id="s0",
+                trim=TrimConfig(duration=1.0),
+                order=-1,
+            ),
+            TrimSegment(
+                segment_id="s1",
+                trim=TrimConfig(duration=1.0),
+                order=-1,
+            ),
+        ]
+        result = resolve_segments(segs, 60.0)
+        assert len(result) == 2
+        # order 为负时使用索引 i，所以 s0 order=0, s1 order=1
+        assert result[0].segment_id == "s0"
+        assert result[1].segment_id == "s1"
+
+    def test_respects_asset_duration(self):
+        segs = [
+            TrimSegment(
+                segment_id="s1",
+                trim=TrimConfig(start_time=50, duration=20.0),  # 超出60s素材
+                order=0,
+            )
+        ]
+        result = resolve_segments(segs, 60.0)
+        assert len(result) == 1
+        assert result[0].trim.end_time == 60.0
+        assert result[0].trim.duration == 10.0
+
+
+# ============================================================
+# parse_segments_from_config
+# ============================================================
+
+
+class TestParseSegmentsFromConfig:
+    def test_none_returns_empty(self):
+        assert parse_segments_from_config(None) == []
+
+    def test_empty_dict_returns_empty(self):
+        assert parse_segments_from_config({}) == []
+
+    def test_trim_segments_list(self):
+        config = {
+            "trim_segments": [
+                {"segment_id": "s1", "start_time": 0, "duration": 5, "order": 0},
+                {"segment_id": "s2", "start_time": 10, "duration": 5, "order": 1},
+            ]
+        }
+        result = parse_segments_from_config(config)
+        assert len(result) == 2
+        assert result[0].segment_id == "s1"
+        assert result[1].segment_id == "s2"
+
+    def test_trim_segments_empty_list(self):
+        config = {"trim_segments": []}
+        result = parse_segments_from_config(config)
+        assert result == []
+
+    def test_trim_segments_not_list_ignored(self):
+        config = {"trim_segments": "not_a_list"}
+        result = parse_segments_from_config(config)
+        assert result == []
+
+    def test_single_trim_start(self):
+        config = {"trim_start": 5.0}
+        result = parse_segments_from_config(config)
+        assert len(result) == 1
+        assert result[0].segment_id == "main"
+        assert result[0].trim.start_time == 5.0
+
+    def test_single_trim_end(self):
+        config = {"trim_end": 30.0}
+        result = parse_segments_from_config(config)
+        assert len(result) == 1
+        assert result[0].trim.end_time == 30.0
+
+    def test_single_trim_duration(self):
+        config = {"trim_duration": 10.0}
+        result = parse_segments_from_config(config)
+        assert len(result) == 1
+        assert result[0].trim.duration == 10.0
+
+    def test_single_full(self):
+        config = {"trim_start": 2.0, "trim_end": 8.0, "trim_duration": 6.0}
+        result = parse_segments_from_config(config)
+        assert len(result) == 1
+        assert result[0].trim.start_time == 2.0
+
+    def test_segments_priority_over_single(self):
+        # 同时有 trim_segments 和单段字段，优先多段
+        config = {
+            "trim_segments": [
+                {"segment_id": "s1", "start_time": 0, "duration": 5},
+            ],
+            "trim_start": 10.0,
+        }
+        result = parse_segments_from_config(config)
+        assert len(result) == 1
+        assert result[0].segment_id == "s1"
+
+    def test_segment_dict_with_non_dict_entries_ignored(self):
+        config = {
+            "trim_segments": [
+                {"segment_id": "s1", "start_time": 0, "duration": 5},
+                "not_a_dict",
+                None,
+            ]
+        }
+        result = parse_segments_from_config(config)
+        assert len(result) == 1
+
+
+# ============================================================
+# extract_trim_from_clip_config
+# ============================================================
+
+
+class TestExtractTrimFromClipConfig:
+    def test_none_returns_none(self):
+        assert extract_trim_from_clip_config(None) is None
+
+    def test_empty_dict_returns_none(self):
+        assert extract_trim_from_clip_config({}) is None
+
+    def test_trim_subdict(self):
+        config = {"trim": {"start_time": 5.0, "duration": 10.0}}
+        result = extract_trim_from_clip_config(config)
+        assert result is not None
+        assert result.start_time == 5.0
+        assert result.duration == 10.0
+
+    def test_trim_subdict_empty(self):
+        config = {"trim": {}}
+        result = extract_trim_from_clip_config(config)
+        assert result is None
+
+    def test_flat_trim_start(self):
+        config = {"trim_start": 5.0, "trim_duration": 10.0}
+        result = extract_trim_from_clip_config(config)
+        assert result is not None
+        assert result.start_time == 5.0
+        assert result.duration == 10.0
+
+    def test_flat_trim_end_only(self):
+        config = {"trim_end": 20.0}
+        result = extract_trim_from_clip_config(config)
+        assert result is not None
+        assert result.end_time == 20.0
+
+    def test_trim_subdict_priority_over_flat(self):
+        # trim子字典优先
+        config = {
+            "trim": {"start_time": 1.0, "duration": 2.0},
+            "trim_start": 10.0,
+            "trim_duration": 20.0,
+        }
+        result = extract_trim_from_clip_config(config)
+        assert result is not None
+        assert result.start_time == 1.0
+        assert result.duration == 2.0
+
+    def test_no_trim_fields(self):
+        config = {"other_field": "value"}
+        assert extract_trim_from_clip_config(config) is None
+
+    def test_trim_not_dict_ignored(self):
+        config = {"trim": "not_a_dict"}
+        # trim 不是 dict，继续看扁平字段 → 没有 → None
+        result = extract_trim_from_clip_config(config)
+        assert result is None