diff --git a/apps/api/app/api/router.py b/apps/api/app/api/router.py
index ec8902fe1..5fdac8e03 100755
--- a/apps/api/app/api/router.py
+++ b/apps/api/app/api/router.py
@@ -13,6 +13,7 @@ from app.api.routes.generated_videos import router as generated_videos_router
 from app.api.routes.generation_tasks import router as generation_tasks_router
 from app.api.routes.health import router as health_check_router
 from app.api.routes.ingest_jobs import router as ingest_jobs_router
+from app.api.routes.internal_render import router as internal_render_router
 from app.api.routes.jobs import router as jobs_router
 from app.api.routes.projects import router as projects_router
 from app.api.routes.recipes import router as recipes_router
@@ -156,3 +157,7 @@ api_router.include_router(
     feature_flags_router,
     tags=["Internal"],
 )
+api_router.include_router(
+    internal_render_router,
+    tags=["Internal"],
+)
diff --git a/apps/api/app/api/routes/internal_render.py b/apps/api/app/api/routes/internal_render.py
new file mode 100755
index 000000000..9d1cf3da3
--- /dev/null
+++ b/apps/api/app/api/routes/internal_render.py
@@ -0,0 +1,120 @@
+"""渲染结果内部下载接口。
+
+通过内部 API Key 鉴权，为灰度对比工具等内部系统提供渲染结果下载能力。
+
+API:
+  GET  /api/v1/internal/render/videos/{video_id}/download-url  - 获取单个视频下载URL
+  GET  /api/v1/internal/render/tasks/{task_id}/videos          - 获取任务下所有视频及下载URL
+
+鉴权：X-API-Key header，走内部 API Key 验证
+"""
+
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+from app.api.routes.auth import _verify_internal_api_key
+from app.core.storage import OSSStorageService, get_storage_service
+from app.dependencies import get_generated_video_repository
+from fastapi import APIRouter, Depends, HTTPException, Query
+from pydantic import BaseModel
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/internal/render", tags=["Internal"])
+
+
+class InternalRenderVideoItem(BaseModel):
+    """内部渲染视频项。"""
+
+    video_id: str
+    generation_task_id: str
+    project_id: str
+    name: str
+    file_url: str
+    file_size: int | None = None
+    duration: float | None = None
+    width: int | None = None
+    height: int | None = None
+    fps: float | None = None
+    status: str
+    download_url: str
+
+
+class InternalRenderTaskVideosResponse(BaseModel):
+    """任务下所有渲染视频响应。"""
+
+    task_id: str
+    count: int
+    videos: list[InternalRenderVideoItem]
+
+
+class InternalRenderDownloadUrlResponse(BaseModel):
+    """单个视频下载URL响应。"""
+
+    video_id: str
+    download_url: str
+
+
+def _video_to_item(video: Any, download_url: str) -> InternalRenderVideoItem:
+    """将 GeneratedVideo 领域对象转为响应项。"""
+    return InternalRenderVideoItem(
+        video_id=video.id,
+        generation_task_id=video.generation_task_id,
+        project_id=video.project_id,
+        name=video.name,
+        file_url=video.file_url,
+        file_size=getattr(video, "file_size", None),
+        duration=getattr(video, "duration", None),
+        width=getattr(video, "width", None),
+        height=getattr(video, "height", None),
+        fps=getattr(video, "fps", None),
+        status=video.status,
+        download_url=download_url,
+    )
+
+
+@router.get("/videos/{video_id}/download-url", response_model=InternalRenderDownloadUrlResponse)
+def get_render_video_download_url(
+    video_id: str,
+    _: bool = Depends(_verify_internal_api_key),
+    generated_video_repository: Any = Depends(get_generated_video_repository),
+    storage_service: OSSStorageService = Depends(get_storage_service),
+) -> InternalRenderDownloadUrlResponse:
+    """获取单个渲染视频的下载URL（预签名）。"""
+    video = generated_video_repository.get(video_id)
+    if video is None:
+        raise HTTPException(status_code=404, detail=f"GeneratedVideo {video_id} not found")
+
+    download_url = storage_service.get_download_url(video.file_url, expires_seconds=86400)
+    logger.info("内部渲染下载URL生成: video_id=%s", video_id)
+    return InternalRenderDownloadUrlResponse(video_id=video_id, download_url=download_url)
+
+
+@router.get("/tasks/{task_id}/videos", response_model=InternalRenderTaskVideosResponse)
+def get_render_task_videos(
+    task_id: str,
+    status: str | None = Query(None, description="按状态筛选，如 completed/failed"),
+    _: bool = Depends(_verify_internal_api_key),
+    generated_video_repository: Any = Depends(get_generated_video_repository),
+    storage_service: OSSStorageService = Depends(get_storage_service),
+) -> InternalRenderTaskVideosResponse:
+    """获取生成任务下所有渲染视频及下载URL。"""
+    videos = generated_video_repository.list_by_generation_task(task_id)
+
+    # 状态筛选
+    if status:
+        videos = [v for v in videos if v.status == status]
+
+    items = []
+    for video in videos:
+        download_url = storage_service.get_download_url(video.file_url, expires_seconds=86400)
+        items.append(_video_to_item(video, download_url))
+
+    logger.info("内部渲染任务视频查询: task_id=%s count=%d", task_id, len(items))
+    return InternalRenderTaskVideosResponse(
+        task_id=task_id,
+        count=len(items),
+        videos=items,
+    )
diff --git a/tests/unit/test_internal_render_download.py b/tests/unit/test_internal_render_download.py
new file mode 100644
index 000000000..c93b1082e
--- /dev/null
+++ b/tests/unit/test_internal_render_download.py
@@ -0,0 +1,190 @@
+"""渲染结果内部下载接口单元测试。
+
+测试 internal_render 路由的核心逻辑，mock 掉 repository 和 storage 依赖。
+"""
+
+from __future__ import annotations
+
+from unittest.mock import MagicMock
+
+import pytest
+from app.api.routes.internal_render import (
+    InternalRenderDownloadUrlResponse,
+    InternalRenderTaskVideosResponse,
+    _video_to_item,
+    get_render_task_videos,
+    get_render_video_download_url,
+)
+
+# ── Helpers ────────────────────────────────────────────────────────────────
+
+
+class MockVideo:
+    """模拟 GeneratedVideo 领域对象。"""
+
+    def __init__(self, **kwargs):
+        self.id = kwargs.get("id", "video-1")
+        self.generation_task_id = kwargs.get("generation_task_id", "task-1")
+        self.project_id = kwargs.get("project_id", "proj-1")
+        self.name = kwargs.get("name", "test_video.mp4")
+        self.file_url = kwargs.get("file_url", "videos/test/output.mp4")
+        self.file_size = kwargs.get("file_size", 1024000)
+        self.duration = kwargs.get("duration", 30.5)
+        self.width = kwargs.get("width", 1080)
+        self.height = kwargs.get("height", 1920)
+        self.fps = kwargs.get("fps", 30.0)
+        self.status = kwargs.get("status", "completed")
+
+
+# ── _video_to_item 测试 ────────────────────────────────────────────────────
+
+
+class TestVideoToItem:
+    """测试视频对象转响应项。"""
+
+    def test_basic_conversion(self):
+        video = MockVideo(id="v1", generation_task_id="t1", status="completed")
+        item = _video_to_item(video, "https://oss.example.com/download?v1")
+        assert item.video_id == "v1"
+        assert item.generation_task_id == "t1"
+        assert item.status == "completed"
+        assert item.download_url == "https://oss.example.com/download?v1"
+
+    def test_missing_optional_fields(self):
+        """缺可选字段时返回 None。"""
+        video = MockVideo()
+        # 去掉可选字段
+        del video.file_size
+        del video.duration
+        item = _video_to_item(video, "https://example.com/dl")
+        assert item.file_size is None
+        assert item.duration is None
+        assert item.width == 1080  # 还在
+
+
+# ── 路由函数测试 ────────────────────────────────────────────────────────────
+
+
+class TestGetRenderVideoDownloadUrl:
+    """测试单个视频下载URL接口。"""
+
+    def test_video_exists(self):
+        video = MockVideo(id="v-abc", file_url="videos/abc/out.mp4")
+        mock_repo = MagicMock()
+        mock_repo.get.return_value = video
+        mock_storage = MagicMock()
+        mock_storage.get_download_url.return_value = "https://oss.test/signed?v=abc"
+
+        result = get_render_video_download_url(
+            video_id="v-abc",
+            _=True,
+            generated_video_repository=mock_repo,
+            storage_service=mock_storage,
+        )
+
+        assert isinstance(result, InternalRenderDownloadUrlResponse)
+        assert result.video_id == "v-abc"
+        assert result.download_url == "https://oss.test/signed?v=abc"
+        mock_repo.get.assert_called_once_with("v-abc")
+        mock_storage.get_download_url.assert_called_once()
+
+    def test_video_not_found_raises_404(self):
+        from fastapi import HTTPException
+
+        mock_repo = MagicMock()
+        mock_repo.get.return_value = None
+        mock_storage = MagicMock()
+
+        with pytest.raises(HTTPException) as exc_info:
+            get_render_video_download_url(
+                video_id="nonexistent",
+                _=True,
+                generated_video_repository=mock_repo,
+                storage_service=mock_storage,
+            )
+        assert exc_info.value.status_code == 404
+
+    def test_download_url_long_expiry(self):
+        """过期时间应为 24 小时（86400s）。"""
+        video = MockVideo(id="v1")
+        mock_repo = MagicMock()
+        mock_repo.get.return_value = video
+        mock_storage = MagicMock()
+        mock_storage.get_download_url.return_value = "https://oss.test/signed"
+
+        get_render_video_download_url(
+            video_id="v1",
+            _=True,
+            generated_video_repository=mock_repo,
+            storage_service=mock_storage,
+        )
+
+        # 验证 expires_seconds=86400
+        call_kwargs = mock_storage.get_download_url.call_args
+        assert call_kwargs.kwargs.get("expires_seconds") == 86400 or call_kwargs[1].get("expires_seconds") == 86400
+
+
+class TestGetRenderTaskVideos:
+    """测试任务视频列表接口。"""
+
+    def test_list_multiple_videos(self):
+        videos = [
+            MockVideo(id="v1", status="completed"),
+            MockVideo(id="v2", status="completed"),
+            MockVideo(id="v3", status="failed"),
+        ]
+        mock_repo = MagicMock()
+        mock_repo.list_by_generation_task.return_value = videos
+        mock_storage = MagicMock()
+        mock_storage.get_download_url.return_value = "https://oss.test/signed"
+
+        result = get_render_task_videos(
+            task_id="task-1",
+            status=None,
+            _=True,
+            generated_video_repository=mock_repo,
+            storage_service=mock_storage,
+        )
+
+        assert isinstance(result, InternalRenderTaskVideosResponse)
+        assert result.task_id == "task-1"
+        assert result.count == 3
+        assert len(result.videos) == 3
+
+    def test_filter_by_status(self):
+        videos = [
+            MockVideo(id="v1", status="completed"),
+            MockVideo(id="v2", status="completed"),
+            MockVideo(id="v3", status="failed"),
+        ]
+        mock_repo = MagicMock()
+        mock_repo.list_by_generation_task.return_value = videos
+        mock_storage = MagicMock()
+        mock_storage.get_download_url.return_value = "https://oss.test/signed"
+
+        result = get_render_task_videos(
+            task_id="task-1",
+            status="completed",
+            _=True,
+            generated_video_repository=mock_repo,
+            storage_service=mock_storage,
+        )
+
+        assert result.count == 2
+        assert all(v.status == "completed" for v in result.videos)
+
+    def test_empty_task(self):
+        mock_repo = MagicMock()
+        mock_repo.list_by_generation_task.return_value = []
+        mock_storage = MagicMock()
+
+        result = get_render_task_videos(
+            task_id="empty-task",
+            status=None,
+            _=True,
+            generated_video_repository=mock_repo,
+            storage_service=mock_storage,
+        )
+
+        assert result.count == 0
+        assert result.videos == []