diff --git a/tests/unit/test_feature_flag.py b/tests/unit/test_feature_flag.py
index 8bab8c04e..99cd76850 100644
--- a/tests/unit/test_feature_flag.py
+++ b/tests/unit/test_feature_flag.py
@@ -1,6 +1,6 @@
 """Feature Flag 单元测试。
 
-测试 FeatureFlagConfig、InMemoryFeatureFlagStore、RenderEngineResolver 的核心逻辑。
+测试 FeatureFlagConfig、InMemoryFeatureFlagStore、RedisFeatureFlagStore 的核心逻辑。
 """
 
 from __future__ import annotations
@@ -184,148 +184,6 @@ class TestInMemoryFeatureFlagStore:
         assert store.is_active("nonexistent") is False
 
 
-# ── RenderEngineResolver 测试 ───────────────────────────────────────────────
-
-
-class TestRenderEngineResolver:
-    """渲染引擎选择器测试。"""
-
-    def test_default_legacy_when_flag_disabled(self):
-        """flag 关闭时使用默认引擎（legacy）。"""
-        store = InMemoryFeatureFlagStore()
-        resolver = self._make_resolver(store=store, default="legacy")
-        assert resolver.get_engine() == "legacy"
-        assert resolver.get_engine("user1") == "legacy"
-
-    def test_default_unified_when_flag_disabled(self):
-        """flag 关闭但默认值是 unified 时返回 unified。"""
-        store = InMemoryFeatureFlagStore()
-        resolver = self._make_resolver(store=store, default="unified")
-        assert resolver.get_engine() == "unified"
-
-    def test_whitelist_user_uses_unified(self):
-        """白名单用户走新引擎。"""
-        store = InMemoryFeatureFlagStore()
-        store.set(
-            FeatureFlagConfig(
-                name="render_engine",
-                enabled=True,
-                percentage=0,
-                whitelist={"beta_tester"},
-            )
-        )
-        resolver = self._make_resolver(store=store, default="legacy")
-        assert resolver.get_engine("beta_tester") == "unified"
-        assert resolver.get_engine("normal_user") == "legacy"
-
-    def test_100_percent_all_unified(self):
-        """100% 时所有用户走新引擎。"""
-        store = InMemoryFeatureFlagStore()
-        store.set(FeatureFlagConfig(name="render_engine", enabled=True, percentage=100))
-        resolver = self._make_resolver(store=store, default="legacy")
-        for i in range(50):
-            assert resolver.get_engine(f"user_{i}") == "unified"
-
-    def test_invalid_default_engine_fallback(self):
-        """无效默认值回退到 legacy。"""
-        store = InMemoryFeatureFlagStore()
-        resolver = self._make_resolver(store=store, default="invalid_value")
-        assert resolver.get_engine() == "legacy"
-
-    def test_should_use_unified_helper(self):
-        """should_use_unified 便捷方法。"""
-        store = InMemoryFeatureFlagStore()
-        store.set(
-            FeatureFlagConfig(
-                name="render_engine",
-                enabled=True,
-                percentage=0,
-                whitelist={"user_a"},
-            )
-        )
-        resolver = self._make_resolver(store=store)
-        assert resolver.should_use_unified("user_a") is True
-        assert resolver.should_use_unified("user_b") is False
-
-    def test_config_snapshot(self):
-        """配置快照。"""
-        store = InMemoryFeatureFlagStore()
-        store.set(
-            FeatureFlagConfig(
-                name="render_engine",
-                enabled=True,
-                percentage=30,
-                whitelist={"u1", "u2"},
-            )
-        )
-        resolver = self._make_resolver(store=store)
-        snapshot = resolver.get_config_snapshot()
-        assert snapshot["flag_name"] == "render_engine"
-        assert snapshot["enabled"] is True
-        assert snapshot["percentage"] == 30
-        assert snapshot["whitelist"] == ["u1", "u2"]
-
-    def test_set_flag_updates_config(self):
-        """通过 set_flag 修改后立即生效。"""
-        store = InMemoryFeatureFlagStore()
-        resolver = self._make_resolver(store=store, default="legacy")
-
-        # 初始：关闭
-        assert resolver.get_engine("user1") == "legacy"
-
-        # 开启 100%
-        resolver.set_flag(FeatureFlagConfig(name="render_engine", enabled=True, percentage=100))
-        assert resolver.get_engine("user1") == "unified"
-
-        # 关闭
-        resolver.set_flag(FeatureFlagConfig(name="render_engine", enabled=False))
-        assert resolver.get_engine("user1") == "legacy"
-
-    def test_force_refresh(self):
-        """强制刷新不报错。"""
-        store = InMemoryFeatureFlagStore()
-        resolver = self._make_resolver(store=store)
-        resolver.force_refresh()  # 不抛异常即可
-
-    def test_does_not_affect_in_flight_tasks(self):
-        """
-        热更新不影响在途任务验证：
-        任务开始时确定引擎，中途配置变更不改变当前任务的引擎选择。
-        （这是通过"每次调用 get_engine 时读取当前配置"来保证的，
-        任务开始时调用一次拿到结果，之后不再变化）
-        """
-        store = InMemoryFeatureFlagStore()
-        store.set(FeatureFlagConfig(name="render_engine", enabled=True, percentage=100))
-        resolver = self._make_resolver(store=store, default="legacy")
-
-        # 模拟任务开始时获取引擎
-        engine_at_start = resolver.get_engine("user1")
-        assert engine_at_start == "unified"
-
-        # 任务进行中关闭 flag
-        store.set(FeatureFlagConfig(name="render_engine", enabled=False))
-        resolver.force_refresh()
-
-        # 在途任务持有的 engine_at_start 仍然是 unified（不随配置变化）
-        assert engine_at_start == "unified"
-        # 新任务会拿到 legacy
-        assert resolver.get_engine("user1") == "legacy"
-
-    # ── 辅助方法 ──
-
-    @staticmethod
-    def _make_resolver(store=None, default="legacy"):
-        from apps.worker.video_processing.render_engine_resolver import (
-            RenderEngineResolver,
-        )
-
-        return RenderEngineResolver(
-            default_engine=default,
-            store=store or InMemoryFeatureFlagStore(),
-            refresh_interval=9999,  # 测试时禁用自动刷新
-        )
-
-
 # ── RedisFeatureFlagStore 降级测试（无 Redis 环境） ───────────────────────