diff --git a/nanobot/channels/dingtalk.py b/nanobot/channels/dingtalk.py
index 8a822ff..ab12211 100644
--- a/nanobot/channels/dingtalk.py
+++ b/nanobot/channels/dingtalk.py
@@ -538,8 +538,8 @@ class DingTalkChannel(BaseChannel):
         filename: str,
         sender_id: str,
     ) -> str | None:
-        """Download a DingTalk file to a local temp directory, return local path."""
-        import tempfile
+        """Download a DingTalk file to the media directory, return local path."""
+        from nanobot.config.paths import get_media_dir
 
         try:
             token = await self._get_access_token()
@@ -568,8 +568,8 @@ class DingTalkChannel(BaseChannel):
                 logger.error("DingTalk file download failed: status={}", file_resp.status_code)
                 return None
 
-            # Save to local temp directory
-            download_dir = Path(tempfile.gettempdir()) / "nanobot_dingtalk" / sender_id
+            # Save to media directory (accessible under workspace)
+            download_dir = get_media_dir("dingtalk") / sender_id
             download_dir.mkdir(parents=True, exist_ok=True)
             file_path = download_dir / filename
             await asyncio.to_thread(file_path.write_bytes, file_resp.content)
diff --git a/tests/test_dingtalk_channel.py b/tests/test_dingtalk_channel.py
index 5bcbcfa..a0b866f 100644
--- a/tests/test_dingtalk_channel.py
+++ b/tests/test_dingtalk_channel.py
@@ -194,14 +194,17 @@ async def test_download_dingtalk_file(tmp_path, monkeypatch) -> None:
     ])
     channel._http._responses[1].content = file_content
 
-    # Redirect temp dir to tmp_path
-    monkeypatch.setattr("tempfile.gettempdir", lambda: str(tmp_path))
+    # Redirect media dir to tmp_path
+    monkeypatch.setattr(
+        "nanobot.config.paths.get_media_dir",
+        lambda channel_name=None: tmp_path / channel_name if channel_name else tmp_path,
+    )
 
     result = await channel._download_dingtalk_file("code123", "test.xlsx", "user1")
 
     assert result is not None
     assert result.endswith("test.xlsx")
-    assert (tmp_path / "nanobot_dingtalk" / "user1" / "test.xlsx").read_bytes() == file_content
+    assert (tmp_path / "dingtalk" / "user1" / "test.xlsx").read_bytes() == file_content
 
     # Verify API calls
     assert channel._http.calls[0]["method"] == "POST"