diff --git a/tests/unit/test_job.py b/tests/unit/test_job.py
new file mode 100644
index 000000000..123bcac11
--- /dev/null
+++ b/tests/unit/test_job.py
@@ -0,0 +1,459 @@
+"""Job 领域模型单测 — 状态机 + 实体方法全覆盖."""
+
+from __future__ import annotations
+
+import pytest
+
+from packages.domain.job import (
+    Job,
+    JobStatus,
+    JobType,
+    TERMINAL_STATUSES,
+)
+
+
+# ── 枚举常量 ────────────────────────────────────────────────────────────────
+
+
+class TestJobType:
+    def test_all_types_exist(self):
+        assert JobType.VIDEO_COMPOSE == "video_compose"
+        assert JobType.RENDER_EDIT_PLAN == "render_edit_plan"
+        assert JobType.ASSET_INGEST == "asset_ingest"
+        assert JobType.CLASSIFICATION == "classification"
+        assert JobType.VOICE_EXTRACTION == "voice_extraction"
+        assert JobType.GENERATION == "generation"
+
+    def test_from_string(self):
+        assert JobType("video_compose") == JobType.VIDEO_COMPOSE
+        assert JobType("render_edit_plan") == JobType.RENDER_EDIT_PLAN
+
+    def test_invalid_type_raises(self):
+        with pytest.raises(ValueError):
+            JobType("invalid_type")
+
+
+class TestJobStatus:
+    def test_all_statuses_exist(self):
+        assert JobStatus.PENDING == "pending"
+        assert JobStatus.RUNNING == "running"
+        assert JobStatus.SUCCESS == "success"
+        assert JobStatus.FAILED == "failed"
+        assert JobStatus.CANCELLED == "cancelled"
+
+    def test_from_string(self):
+        assert JobStatus("pending") == JobStatus.PENDING
+        assert JobStatus("running") == JobStatus.RUNNING
+
+
+class TestTerminalStatuses:
+    def test_success_is_terminal(self):
+        assert JobStatus.SUCCESS in TERMINAL_STATUSES
+
+    def test_failed_is_terminal(self):
+        assert JobStatus.FAILED in TERMINAL_STATUSES
+
+    def test_cancelled_is_terminal(self):
+        assert JobStatus.CANCELLED in TERMINAL_STATUSES
+
+    def test_pending_not_terminal(self):
+        assert JobStatus.PENDING not in TERMINAL_STATUSES
+
+    def test_running_not_terminal(self):
+        assert JobStatus.RUNNING not in TERMINAL_STATUSES
+
+
+# ── Job.create ─────────────────────────────────────────────────────────────
+
+
+class TestJobCreate:
+    def test_basic_creation(self):
+        job = Job.create(project_id="proj_1", job_type=JobType.VIDEO_COMPOSE)
+        assert job.id  # 自动生成
+        assert job.project_id == "proj_1"
+        assert job.job_type == JobType.VIDEO_COMPOSE
+        assert job.status == JobStatus.PENDING
+        assert job.progress == 0.0
+        assert job.retry_count == 0
+        assert job.max_retries == 3
+        assert job.payload == {}
+        assert job.result == {}
+
+    def test_job_type_string_conversion(self):
+        job = Job.create(project_id="proj_1", job_type="video_compose")
+        assert job.job_type == JobType.VIDEO_COMPOSE
+
+    def test_invalid_job_type_raises(self):
+        with pytest.raises(ValueError, match="不支持的任务类型"):
+            Job.create(project_id="proj_1", job_type="invalid")
+
+    def test_empty_project_id_raises(self):
+        with pytest.raises(ValueError, match="project_id 不能为空"):
+            Job.create(project_id="  ", job_type=JobType.VIDEO_COMPOSE)
+
+    def test_project_id_stripped(self):
+        job = Job.create(project_id="  proj_1  ", job_type=JobType.VIDEO_COMPOSE)
+        assert job.project_id == "proj_1"
+
+    def test_with_payload(self):
+        payload = {"video_url": "http://example.com/v.mp4"}
+        job = Job.create(project_id="proj_1", job_type=JobType.VIDEO_COMPOSE, payload=payload)
+        assert job.payload == payload
+
+    def test_payload_none_defaults_empty_dict(self):
+        job = Job.create(project_id="proj_1", job_type=JobType.VIDEO_COMPOSE, payload=None)
+        assert job.payload == {}
+
+    def test_with_source_id(self):
+        job = Job.create(project_id="proj_1", job_type=JobType.VIDEO_COMPOSE, source_id="plan_123")
+        assert job.source_id == "plan_123"
+
+    def test_source_id_stripped(self):
+        job = Job.create(project_id="proj_1", job_type=JobType.VIDEO_COMPOSE, source_id="  src  ")
+        assert job.source_id == "src"
+
+    def test_with_created_by(self):
+        job = Job.create(project_id="proj_1", job_type=JobType.VIDEO_COMPOSE, created_by_user_id="user_1")
+        assert job.created_by_user_id == "user_1"
+
+    def test_custom_max_retries(self):
+        job = Job.create(project_id="proj_1", job_type=JobType.VIDEO_COMPOSE, max_retries=5)
+        assert job.max_retries == 5
+
+    def test_created_at_auto_set(self):
+        job = Job.create(project_id="proj_1", job_type=JobType.VIDEO_COMPOSE)
+        assert job.created_at is not None
+        assert job.updated_at is not None
+
+    def test_started_at_none_initially(self):
+        job = Job.create(project_id="proj_1", job_type=JobType.VIDEO_COMPOSE)
+        assert job.started_at is None
+        assert job.completed_at is None
+
+
+# ── 属性判断 ────────────────────────────────────────────────────────────────
+
+
+class TestJobProperties:
+    def test_is_terminal_pending_false(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        assert not job.is_terminal
+
+    def test_is_terminal_running_false(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        assert not job.is_terminal
+
+    def test_is_terminal_success_true(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.SUCCESS)
+        assert job.is_terminal
+
+    def test_is_terminal_failed_true(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.FAILED)
+        assert job.is_terminal
+
+    def test_is_terminal_cancelled_true(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.CANCELLED)
+        assert job.is_terminal
+
+    def test_is_retryable_failed_within_limit(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE, max_retries=3)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.FAILED)
+        assert job.is_retryable
+
+    def test_is_retryable_failed_at_limit(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE, max_retries=3)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.FAILED)
+        job.retry_count = 3
+        assert not job.is_retryable
+
+    def test_is_retryable_pending_false(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        assert not job.is_retryable
+
+    def test_is_retryable_success_false(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.SUCCESS)
+        assert not job.is_retryable
+
+
+# ── 状态转换 ────────────────────────────────────────────────────────────────
+
+
+class TestTransitionTo:
+    def test_pending_to_running(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        assert job.status == JobStatus.RUNNING
+
+    def test_pending_to_success(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.SUCCESS)
+        assert job.status == JobStatus.SUCCESS
+
+    def test_pending_to_cancelled(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.CANCELLED)
+        assert job.status == JobStatus.CANCELLED
+
+    def test_running_to_success(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.SUCCESS)
+        assert job.status == JobStatus.SUCCESS
+
+    def test_running_to_failed(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.FAILED)
+        assert job.status == JobStatus.FAILED
+
+    def test_running_to_cancelled(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.CANCELLED)
+        assert job.status == JobStatus.CANCELLED
+
+    def test_failed_to_pending_retry(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.FAILED)
+        job.transition_to(JobStatus.PENDING)
+        assert job.status == JobStatus.PENDING
+
+    def test_invalid_transition_raises(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        # success → running 是非法的
+        job.transition_to(JobStatus.SUCCESS)
+        with pytest.raises(ValueError, match="非法状态转换"):
+            job.transition_to(JobStatus.RUNNING)
+
+    def test_string_status_conversion(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to("running")
+        assert job.status == JobStatus.RUNNING
+
+    def test_invalid_string_status_raises(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        with pytest.raises(ValueError, match="无效状态"):
+            job.transition_to("invalid_status")
+
+    def test_transition_updates_updated_at(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        old_updated = job.updated_at
+        import time; time.sleep(0.001)
+        job.transition_to(JobStatus.RUNNING)
+        assert job.updated_at >= old_updated
+
+    def test_running_sets_started_at(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        assert job.started_at is None
+        job.transition_to(JobStatus.RUNNING)
+        assert job.started_at is not None
+
+    def test_success_sets_completed_at(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        assert job.completed_at is None
+        job.transition_to(JobStatus.SUCCESS)
+        assert job.completed_at is not None
+
+    def test_failed_sets_completed_at(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.transition_to(JobStatus.FAILED)
+        assert job.completed_at is not None
+
+
+# ── 便捷方法 ────────────────────────────────────────────────────────────────
+
+
+class TestMarkMethods:
+    def test_mark_running(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.mark_running(stage="初始化")
+        assert job.status == JobStatus.RUNNING
+        assert job.current_stage == "初始化"
+
+    def test_mark_running_no_stage(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.mark_running()
+        assert job.status == JobStatus.RUNNING
+        assert job.current_stage == ""
+
+    def test_mark_success(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        result = {"output_url": "http://example.com/out.mp4"}
+        job.mark_success(result=result)
+        assert job.status == JobStatus.SUCCESS
+        assert job.progress == 100.0
+        assert job.current_stage == "完成"
+        assert job.result == result
+
+    def test_mark_success_no_result(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.mark_success()
+        assert job.status == JobStatus.SUCCESS
+        assert job.result == {}  # 保持默认空字典
+
+    def test_mark_failed(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.mark_failed("网络超时")
+        assert job.status == JobStatus.FAILED
+        assert job.error_message == "网络超时"
+        assert job.current_stage == "失败"
+
+    def test_mark_cancelled(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.mark_cancelled()
+        assert job.status == JobStatus.CANCELLED
+        assert job.current_stage == "已取消"
+
+
+# ── 进度更新 ────────────────────────────────────────────────────────────────
+
+
+class TestUpdateProgress:
+    def test_normal_progress(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.update_progress(50.0, stage="渲染中")
+        assert job.progress == 50.0
+        assert job.current_stage == "渲染中"
+
+    def test_progress_zero(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.update_progress(0.0)
+        assert job.progress == 0.0
+
+    def test_progress_100(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.update_progress(100.0)
+        assert job.progress == 100.0
+
+    def test_progress_negative_raises(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        with pytest.raises(ValueError, match="进度必须在 0~100 之间"):
+            job.update_progress(-1.0)
+
+    def test_progress_over_100_raises(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        with pytest.raises(ValueError, match="进度必须在 0~100 之间"):
+            job.update_progress(100.1)
+
+    def test_progress_without_stage(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.update_progress(30.0)
+        assert job.progress == 30.0
+
+    def test_progress_updates_updated_at(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        old_updated = job.updated_at
+        import time; time.sleep(0.001)
+        job.update_progress(50.0)
+        assert job.updated_at > old_updated
+
+
+# ── 重试 ────────────────────────────────────────────────────────────────────
+
+
+class TestPrepareRetry:
+    def test_normal_retry(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE, max_retries=3)
+        job.transition_to(JobStatus.RUNNING)
+        job.mark_failed("超时")
+        job.prepare_retry()
+        assert job.status == JobStatus.PENDING
+        assert job.retry_count == 1
+        assert job.progress == 0.0
+        assert "第 1 次重试" in job.current_stage
+        assert job.error_message == ""
+        assert job.started_at is None
+        assert job.completed_at is None
+        assert job.celery_task_id == ""
+
+    def test_retry_increments_count(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE, max_retries=3)
+        job.transition_to(JobStatus.RUNNING)
+        job.mark_failed("超时")
+        job.prepare_retry()
+        assert job.retry_count == 1
+        job.transition_to(JobStatus.RUNNING)
+        job.mark_failed("又超时了")
+        job.prepare_retry()
+        assert job.retry_count == 2
+
+    def test_retry_exceeds_limit_raises(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE, max_retries=1)
+        job.transition_to(JobStatus.RUNNING)
+        job.mark_failed("超时")
+        job.prepare_retry()  # 第1次重试，ok
+        job.transition_to(JobStatus.RUNNING)
+        job.mark_failed("又超时了")
+        # retry_count=1, max_retries=1 → 不能再重试
+        with pytest.raises(ValueError, match="不可重试"):
+            job.prepare_retry()
+
+    def test_retry_from_success_raises(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.transition_to(JobStatus.RUNNING)
+        job.mark_success()
+        with pytest.raises(ValueError, match="不可重试"):
+            job.prepare_retry()
+
+    def test_retry_from_pending_raises(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        with pytest.raises(ValueError, match="不可重试"):
+            job.prepare_retry()
+
+
+# ── 序列化 ──────────────────────────────────────────────────────────────────
+
+
+class TestToDict:
+    def test_basic_fields(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE, source_id="src1")
+        d = job.to_dict()
+        assert d["id"] == job.id
+        assert d["project_id"] == "p1"
+        assert d["job_type"] == "video_compose"
+        assert d["status"] == "pending"
+        assert d["progress"] == 0.0
+        assert d["source_id"] == "src1"
+        assert d["retry_count"] == 0
+        assert d["max_retries"] == 3
+
+    def test_is_retryable_in_output(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        d = job.to_dict()
+        assert "is_retryable" in d
+        assert d["is_retryable"] is False
+
+    def test_datetime_fields_are_strings(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        d = job.to_dict()
+        assert isinstance(d["created_at"], str)
+        assert isinstance(d["updated_at"], str)
+
+    def test_started_at_none_when_not_started(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        d = job.to_dict()
+        assert d["started_at"] is None
+        assert d["completed_at"] is None
+
+    def test_started_at_present_after_running(self):
+        job = Job.create(project_id="p1", job_type=JobType.VIDEO_COMPOSE)
+        job.mark_running()
+        d = job.to_dict()
+        assert d["started_at"] is not None
+        assert isinstance(d["started_at"], str)