diff --git a/workflow_service/comfy/comfy_workflow.py b/workflow_service/comfy/comfy_workflow.py
index a556cf0..0c4db3e 100644
--- a/workflow_service/comfy/comfy_workflow.py
+++ b/workflow_service/comfy/comfy_workflow.py
@@ -409,7 +409,7 @@ def _generate_field_schema(input_field: dict) -> dict:
         )
     elif field_type == "UploadFile":
         field_schema.update(
-            {"type": "string", "format": "binary", "description": "上传文件"}
+            {"type": "string", "format": "binary", "contentMediaType": "image/*", "description": "上传文件"}
         )
     else:  # string
         field_schema.update({"type": "string"})