diff --git a/api/app/services/workflow_service.py b/api/app/services/workflow_service.py
index 22fa70eb..db50ce88 100644
--- a/api/app/services/workflow_service.py
+++ b/api/app/services/workflow_service.py
@@ -2,6 +2,7 @@
 工作流服务层
 """
 import datetime
+import json
 import logging
 import uuid
 from typing import Any, Annotated, Optional
@@ -447,9 +448,13 @@ class WorkflowService:
                 message=f"工作流配置不存在: app_id={app_id}"
             )
 
+        json_files = []
+        for file in payload.files:
+            file_json = json.loads(file.model_dump_json())
+            json_files.append(file_json)
         input_data = {"message": payload.message, "variables": payload.variables,
                       "conversation_id": payload.conversation_id,
-                      "files": [file.model_dump() for file in payload.files] if payload.files else []
+                      "files": json_files
                       }
 
         # 转换 conversation_id 为 UUID
@@ -636,9 +641,14 @@ class WorkflowService:
                 code=BizCode.CONFIG_MISSING,
                 message=f"工作流配置不存在: app_id={app_id}"
             )
+
+        json_files = []
+        for file in payload.files:
+            file_json = json.loads(file.model_dump_json())
+            json_files.append(file_json)
         input_data = {"message": payload.message, "variables": payload.variables,
                       "conversation_id": payload.conversation_id,
-                      "files": [file.model_dump() for file in payload.files] if payload.files else []
+                      "files": json_files
                       }
 
         # 转换 conversation_id 为 UUID