diff --git a/th_agenter/services/workflow_engine.py b/th_agenter/services/workflow_engine.py
index ee12812..5ad3b66 100644
--- a/th_agenter/services/workflow_engine.py
+++ b/th_agenter/services/workflow_engine.py
@@ -582,8 +582,8 @@ class WorkflowEngine:
         previous_outputs = input_data.get('previous_outputs', {})
         
         # 处理结束节点的输出参数配置
-        node_parameters = node.get('parameters', {})
-        output_params = node_parameters.get('outputs', [])
+        node_parameters = node.get('parameters') or {}
+        output_params = node_parameters.get('outputs', []) if isinstance(node_parameters, dict) else []
         
         result_data = {}
         
@@ -652,7 +652,7 @@ class WorkflowEngine:
     
     async def _execute_llm_node(self, node: Dict[str, Any], input_data: Dict[str, Any]) -> Dict[str, Any]:
         """执行LLM节点"""
-        config = input_data['node_config']
+        config = input_data.get('node_config', {})
         
         # 获取LLM配置
         model_id = config.get('model_id')
@@ -673,8 +673,41 @@ class WorkflowEngine:
                     if llm_config:
                         model_id = llm_config.id
         
+        # 如果还是没有，尝试从节点定义本身获取
         if not model_id:
-            raise ValueError("未指定有效的大模型配置")
+            node_config = node.get('config', {})
+            model_id = node_config.get('model_id')
+            if not model_id:
+                model_value = node_config.get('model_name', node_config.get('model'))
+                if model_value:
+                    if isinstance(model_value, int):
+                        model_id = model_value
+                    else:
+                        from sqlalchemy import select
+                        result = await self.session.execute(
+                            select(LLMConfig).where(LLMConfig.model_name == model_value)
+                        )
+                        llm_config = result.scalar_one_or_none()
+                        if llm_config:
+                            model_id = llm_config.id
+        
+        # 如果还是没有，尝试使用默认的LLM配置
+        if not model_id:
+            from ..services.llm_config_service import LLMConfigService
+            llm_config_service = LLMConfigService()
+            default_config = await llm_config_service.get_default_chat_config(self.session)
+            if default_config:
+                model_id = default_config.id
+                logger.info(f"LLM节点未指定模型配置，使用默认模型: {default_config.model_name} (ID: {model_id})")
+            else:
+                raise ValueError(
+                    "未指定有效的大模型配置，且未找到默认配置。\n"
+                    "请在节点配置中添加模型ID或模型名称，例如：\n"
+                    "  - config.model_id: 1\n"
+                    "  - config.model_name: 'gpt-4'\n"
+                    "  - config.model: 'gpt-4'\n"
+                    "或者设置一个默认的LLM配置。"
+                )
         
         from sqlalchemy import select
         result = await self.session.execute(