diff --git a/astrbot/core/platform/sources/weixin_oc/weixin_oc_adapter.py b/astrbot/core/platform/sources/weixin_oc/weixin_oc_adapter.py
index 5069795729..abb4c95999 100644
--- a/astrbot/core/platform/sources/weixin_oc/weixin_oc_adapter.py
+++ b/astrbot/core/platform/sources/weixin_oc/weixin_oc_adapter.py
@@ -593,10 +593,10 @@ async def _prepare_media_item(
             len(str(payload.get("upload_param", ""))),
         )
         upload_param = str(payload.get("upload_param", "")).strip()
-        if not upload_param:
-            raise RuntimeError("getuploadurl returned empty upload_param")
+        upload_full_url = str(payload.get("upload_full_url", "")).strip()
 
         encrypted_query_param = await self.client.upload_to_cdn(
+            upload_full_url,
             upload_param,
             file_key,
             aes_key_hex,
diff --git a/astrbot/core/platform/sources/weixin_oc/weixin_oc_client.py b/astrbot/core/platform/sources/weixin_oc/weixin_oc_client.py
index 51b0b6ed7c..1ea44df527 100644
--- a/astrbot/core/platform/sources/weixin_oc/weixin_oc_client.py
+++ b/astrbot/core/platform/sources/weixin_oc/weixin_oc_client.py
@@ -108,11 +108,21 @@ def parse_media_aes_key(aes_key_value: str) -> bytes:
 
     async def upload_to_cdn(
         self,
+        upload_full_url: str,
         upload_param: str,
         file_key: str,
         aes_key_hex: str,
         media_path: Path,
     ) -> str:
+        if upload_full_url:
+            cdn_url = upload_full_url
+        elif upload_param:
+            cdn_url = self._build_cdn_upload_url(upload_param, file_key)
+        else:
+            raise ValueError(
+                "CDN upload URL missing (need upload_full_url or upload_param)"
+            )
+
         raw_data = media_path.read_bytes()
         logger.debug(
             "weixin_oc(%s): prepare CDN upload file=%s size=%s md5=%s filekey=%s",
@@ -135,7 +145,6 @@ async def upload_to_cdn(
         await self.ensure_http_session()
         assert self._http_session is not None
         timeout = aiohttp.ClientTimeout(total=self.api_timeout_ms / 1000)
-        cdn_url = self._build_cdn_upload_url(upload_param, file_key)
 
         async with self._http_session.post(
             cdn_url,