diff --git a/README.md b/README.md
index 51f14a4..9843ea0 100644
--- a/README.md
+++ b/README.md
@@ -78,6 +78,7 @@ cp config-template.json config.json
 
 + `clear_memory_commands`: 对话内指令，主动清空前文记忆，字符串数组可自定义指令别名。
   + default: ["#清除记忆"]
++ `max_history_per_session`[optional]: 对话最大记忆长度，超过该长度则清理前面的记忆。
 
 ## 二、选择模型
 
diff --git a/model/openai/chatgpt_model.py b/model/openai/chatgpt_model.py
index 9a8f3d6..7cf6cfc 100644
--- a/model/openai/chatgpt_model.py
+++ b/model/openai/chatgpt_model.py
@@ -196,6 +196,7 @@ class Session(object):
     @staticmethod
     def save_session(query, answer, user_id, used_tokens=0):
         max_tokens = model_conf(const.OPEN_AI).get('conversation_max_tokens')
+        max_history_per_session = model_conf(const.OPEN_AI).get('max_history_per_session', None)
         if not max_tokens or max_tokens > 4000:
             # default value
             max_tokens = 1000
@@ -210,6 +211,10 @@ class Session(object):
             session.pop(1)
             session.pop(1)
 
+        if max_history_per_session is not None:
+            while len(session) > max_history_per_session + 1:
+                session.pop(1)
+
     @staticmethod
     def clear_session(user_id):
         user_session[user_id] = []