diff --git a/metagpt/context.py b/metagpt/context.py
index 495fe9e2f..ba859ed5c 100644
--- a/metagpt/context.py
+++ b/metagpt/context.py
@@ -45,24 +45,24 @@ class AttrDict(BaseModel):
 class LLMMixin:
     """Mixin class for LLM"""
 
-    config: Optional[Config] = None
-    llm_config: Optional[LLMConfig] = None
+    # _config: Optional[Config] = None
+    _llm_config: Optional[LLMConfig] = None
     _llm_instance: Optional[BaseLLM] = None
 
     def use_llm(self, name: Optional[str] = None, provider: LLMType = LLMType.OPENAI):
         """Use a LLM provider"""
         # 更新LLM配置
-        self.llm_config = self.config.get_llm_config(name, provider)
+        self._llm_config = self._config.get_llm_config(name, provider)
         # 重置LLM实例
         self._llm_instance = None
 
     @property
     def llm(self) -> BaseLLM:
         """Return the LLM instance"""
-        if not self.llm_config:
+        if not self._llm_config:
             self.use_llm()
-        if not self._llm_instance and self.llm_config:
-            self._llm_instance = create_llm_instance(self.llm_config)
+        if not self._llm_instance and self._llm_config:
+            self._llm_instance = create_llm_instance(self._llm_config)
         return self._llm_instance