diff --git a/apps/api/app/api/routes/assets.py b/apps/api/app/api/routes/assets.py
index 187c59711..58c0ce30b 100644
--- a/apps/api/app/api/routes/assets.py
+++ b/apps/api/app/api/routes/assets.py
@@ -8,7 +8,13 @@ from app.dependencies import (
     get_asset_repository,
     get_project_repository,
 )
-from app.schemas.asset import AssetResponse, CreateAssetRequest, ListAssetsResponse, UpdateAssetReviewRequest
+from app.schemas.asset import (
+    AssetResponse,
+    CreateAssetRequest,
+    ListAssetsResponse,
+    UpdateAssetRequest,
+    UpdateAssetReviewRequest,
+)
 from fastapi import APIRouter, Depends, HTTPException, Query
 
 from packages.application import (
@@ -75,6 +81,7 @@ def _check_project_access(project_id: str, user_id: str, project_repository) ->
 def list_assets(
     library_id: Optional[str] = Query(None),
     project_id: Optional[str] = Query(None),
+    kind: Optional[str] = Query(None, pattern="^(video|voice|image)$"),
     authenticated_user: AuthenticatedUser = Depends(get_current_user),
     asset_repository: Any = Depends(get_asset_repository),
     asset_library_repository: Any = Depends(get_asset_library_repository),
@@ -82,20 +89,32 @@ def list_assets(
 ) -> ListAssetsResponse:
     user_id = authenticated_user.user.id
 
+    # kind → file_type 映射（voice 对应 audio）
+    kind_to_file_type = {"video": "video", "voice": "audio", "image": "image"}
+
+    def _filter_by_kind(items):
+        if not kind:
+            return items
+        ft = kind_to_file_type.get(kind)
+        return [item for item in items if item.mime_type and item.mime_type.startswith(ft or "")]
+
     # 模式1：指定 library_id → 返回该库的素材
     if library_id:
         library = asset_library_repository.get(library_id)
         if library is None:
             raise HTTPException(status_code=404, detail=f"AssetLibrary {library_id} not found")
         _check_project_access(library.project_id, user_id, project_repository)
-        items = asset_repository.find_by_library(library_id)
+        if kind:
+            items = asset_repository.find_by_library_and_file_type(library_id, kind_to_file_type[kind])
+        else:
+            items = asset_repository.find_by_library(library_id)
         return ListAssetsResponse(items=[_to_asset_response(item) for item in items])
 
     # 模式2：指定 project_id → 返回该项目所有素材
     if project_id:
         _check_project_access(project_id, user_id, project_repository)
         items = asset_repository.find_by_project(project_id)
-        return ListAssetsResponse(items=[_to_asset_response(item) for item in items])
+        return ListAssetsResponse(items=[_to_asset_response(item) for item in _filter_by_kind(items)])
 
     # 模式3：都不传 → 返回用户可访问的所有项目的所有素材
     try:
@@ -107,7 +126,7 @@ def list_assets(
     all_items = []
     for proj in projects:
         all_items.extend(asset_repository.find_by_project(proj.id))
-    return ListAssetsResponse(items=[_to_asset_response(item) for item in all_items])
+    return ListAssetsResponse(items=[_to_asset_response(item) for item in _filter_by_kind(all_items)])
 
 
 def _apply_asset_review_status(item, review_status: str):
@@ -135,6 +154,59 @@ def update_asset_review_status(
     return _to_asset_response(updated)
 
 
+@router.get("/{asset_id}", response_model=AssetResponse)
+def get_asset(
+    asset_id: str,
+    authenticated_user: AuthenticatedUser = Depends(get_current_user),
+    asset_repository: Any = Depends(get_asset_repository),
+    project_repository: Any = Depends(get_project_repository),
+) -> AssetResponse:
+    item = asset_repository.find_by_id(asset_id)
+    if item is None:
+        raise HTTPException(status_code=404, detail=f"Asset {asset_id} not found")
+    _check_project_access(item.project_id, authenticated_user.user.id, project_repository)
+    return _to_asset_response(item)
+
+
+@router.put("/{asset_id}", response_model=AssetResponse)
+def update_asset(
+    asset_id: str,
+    request: UpdateAssetRequest,
+    authenticated_user: AuthenticatedUser = Depends(get_current_user),
+    asset_repository: Any = Depends(get_asset_repository),
+    project_repository: Any = Depends(get_project_repository),
+) -> AssetResponse:
+    item = asset_repository.find_by_id(asset_id)
+    if item is None:
+        raise HTTPException(status_code=404, detail=f"Asset {asset_id} not found")
+    _check_project_access(item.project_id, authenticated_user.user.id, project_repository)
+
+    # 合并可修改字段
+    if request.name is not None:
+        item.name = request.name
+    if request.metadata is not None:
+        item.metadata = {**item.metadata, **request.metadata}
+    if request.tags is not None:
+        item.metadata = {**item.metadata, "tags": request.tags}
+
+    updated = asset_repository.update(item)
+    return _to_asset_response(updated)
+
+
+@router.delete("/{asset_id}", status_code=204)
+def delete_asset(
+    asset_id: str,
+    authenticated_user: AuthenticatedUser = Depends(get_current_user),
+    asset_repository: Any = Depends(get_asset_repository),
+    project_repository: Any = Depends(get_project_repository),
+) -> None:
+    item = asset_repository.find_by_id(asset_id)
+    if item is None:
+        raise HTTPException(status_code=404, detail=f"Asset {asset_id} not found")
+    _check_project_access(item.project_id, authenticated_user.user.id, project_repository)
+    asset_repository.delete(asset_id)
+
+
 @router.post("", response_model=AssetResponse)
 def create_asset(
     request: CreateAssetRequest,
diff --git a/apps/api/app/schemas/asset.py b/apps/api/app/schemas/asset.py
index ac2e8fb4b..d08f40a57 100644
--- a/apps/api/app/schemas/asset.py
+++ b/apps/api/app/schemas/asset.py
@@ -25,6 +25,12 @@ class UpdateAssetReviewRequest(BaseModel):
     review_status: str = Field(..., pattern="^(pending_review|approved|rejected)$")
 
 
+class UpdateAssetRequest(BaseModel):
+    name: str | None = Field(default=None, min_length=1, max_length=100)
+    metadata: dict[str, object] | None = None
+    tags: list[str] | None = None
+
+
 class AssetResponse(BaseModel):
     id: str
     project_id: str
diff --git a/packages/adapters/in_memory/asset_repository.py b/packages/adapters/in_memory/asset_repository.py
index 3a3393967..7b6874a43 100755
--- a/packages/adapters/in_memory/asset_repository.py
+++ b/packages/adapters/in_memory/asset_repository.py
@@ -26,6 +26,13 @@ class InMemoryAssetRepository:
         """Alias for list_by_library to match the port interface."""
         return self.list_by_library(library_id)
 
+    def find_by_library_and_file_type(self, library_id: str, file_type: str) -> list[Asset]:
+        return [
+            asset
+            for asset in self._assets.values()
+            if asset.library_id == library_id and asset.mime_type and asset.mime_type.startswith(file_type)
+        ]
+
     def update(self, asset: Asset) -> Asset:
         self._assets[asset.id] = asset
         return asset
diff --git a/packages/adapters/sqlalchemy_impl/asset_repository.py b/packages/adapters/sqlalchemy_impl/asset_repository.py
index e0eef97a9..d14fa3e9f 100644
--- a/packages/adapters/sqlalchemy_impl/asset_repository.py
+++ b/packages/adapters/sqlalchemy_impl/asset_repository.py
@@ -37,6 +37,22 @@ class SQLAlchemyAssetRepository:
         )
         return [self._to_domain(model) for model in models]
 
+    def find_by_library_and_file_type(
+        self,
+        library_id: str,
+        file_type: str,
+        skip: int = 0,
+        limit: int = 100,
+    ) -> list[Asset]:
+        models = (
+            self.session.query(AssetModel)
+            .filter(AssetModel.asset_library_id == library_id, AssetModel.file_type == file_type)
+            .offset(skip)
+            .limit(limit)
+            .all()
+        )
+        return [self._to_domain(model) for model in models]
+
     def find_by_id(self, asset_id: str) -> Asset | None:
         model = self.session.query(AssetModel).filter(AssetModel.id == asset_id).first()
         if model is None:
diff --git a/packages/ports/asset_repository.py b/packages/ports/asset_repository.py
index e5643a77f..3bee42356 100644
--- a/packages/ports/asset_repository.py
+++ b/packages/ports/asset_repository.py
@@ -32,6 +32,16 @@ class AssetRepository(ABC):
     ) -> list[Asset]:
         pass
 
+    @abstractmethod
+    def find_by_library_and_file_type(
+        self,
+        library_id: str,
+        file_type: str,
+        skip: int = 0,
+        limit: int = 100,
+    ) -> list[Asset]:
+        pass
+
     @abstractmethod
     def update(self, asset: Asset) -> Asset:
         pass