diff --git a/dbgpt/core/interface/message.py b/dbgpt/core/interface/message.py
old mode 100644
new mode 100755
index bd06f0dc7..2b1439c6d
--- a/dbgpt/core/interface/message.py
+++ b/dbgpt/core/interface/message.py
@@ -157,14 +157,13 @@ def to_openai_messages(messages: List["ModelMessage"]) -> List[Dict[str, str]]:
             else:
                 pass
         # Move the last user's information to the end
-        temp_his = history[::-1]
-        last_user_input = None
-        for m in temp_his:
-            if m["role"] == "user":
-                last_user_input = m
+        last_user_input_index = None
+        for i in range(len(history) - 1, -1, -1):
+            if history[i]["role"] == "user":
+                last_user_input_index = i
                 break
-        if last_user_input:
-            history.remove(last_user_input)
+        if last_user_input_index:
+            last_user_input = history.pop(last_user_input_index)
             history.append(last_user_input)
         return history
 
diff --git a/dbgpt/core/interface/tests/test_message.py b/dbgpt/core/interface/tests/test_message.py
old mode 100644
new mode 100755
index 425f268af..41f5f36c5
--- a/dbgpt/core/interface/tests/test_message.py
+++ b/dbgpt/core/interface/tests/test_message.py
@@ -67,6 +67,23 @@ def conversation_with_messages():
     return conv
 
 
+@pytest.fixture
+def human_model_message():
+    return ModelMessage(role=ModelMessageRoleType.HUMAN, content="Hello")
+
+
+@pytest.fixture
+def ai_model_message():
+    return ModelMessage(role=ModelMessageRoleType.AI, content="Hi there")
+
+
+@pytest.fixture
+def system_model_message():
+    return ModelMessage(
+        role=ModelMessageRoleType.SYSTEM, content="You are a helpful chatbot!"
+    )
+
+
 def test_init(basic_conversation):
     assert basic_conversation.chat_mode == "chat_normal"
     assert basic_conversation.user_name == "user1"
@@ -305,3 +322,43 @@ def test_load_from_storage(storage_conversation, in_memory_storage):
     assert new_conversation.messages[1].content == "AI response"
     assert isinstance(new_conversation.messages[0], HumanMessage)
     assert isinstance(new_conversation.messages[1], AIMessage)
+
+
+def test_to_openai_messages(
+    human_model_message, ai_model_message, system_model_message
+):
+    none_messages = ModelMessage.to_openai_messages([])
+    assert none_messages == []
+
+    single_messages = ModelMessage.to_openai_messages([human_model_message])
+    assert single_messages == [{"role": "user", "content": human_model_message.content}]
+
+    normal_messages = ModelMessage.to_openai_messages(
+        [
+            system_model_message,
+            human_model_message,
+            ai_model_message,
+            human_model_message,
+        ]
+    )
+    assert normal_messages == [
+        {"role": "system", "content": system_model_message.content},
+        {"role": "user", "content": human_model_message.content},
+        {"role": "assistant", "content": ai_model_message.content},
+        {"role": "user", "content": human_model_message.content},
+    ]
+
+    shuffle_messages = ModelMessage.to_openai_messages(
+        [
+            system_model_message,
+            human_model_message,
+            human_model_message,
+            ai_model_message,
+        ]
+    )
+    assert shuffle_messages == [
+        {"role": "system", "content": system_model_message.content},
+        {"role": "user", "content": human_model_message.content},
+        {"role": "assistant", "content": ai_model_message.content},
+        {"role": "user", "content": human_model_message.content},
+    ]
diff --git a/dbgpt/model/proxy/llms/bard.py b/dbgpt/model/proxy/llms/bard.py
old mode 100644
new mode 100755
index 5b6ed26a0..fc398fe8b
--- a/dbgpt/model/proxy/llms/bard.py
+++ b/dbgpt/model/proxy/llms/bard.py
@@ -25,14 +25,13 @@ def bard_generate_stream(
         else:
             pass
 
-    temp_his = history[::-1]
-    last_user_input = None
-    for m in temp_his:
-        if m["role"] == "user":
-            last_user_input = m
+    last_user_input_index = None
+    for i in range(len(history) - 1, -1, -1):
+        if history[i]["role"] == "user":
+            last_user_input_index = i
             break
-    if last_user_input:
-        history.remove(last_user_input)
+    if last_user_input_index:
+        last_user_input = history.pop(last_user_input_index)
         history.append(last_user_input)
 
     msgs = []
diff --git a/dbgpt/model/proxy/llms/chatgpt.py b/dbgpt/model/proxy/llms/chatgpt.py
old mode 100644
new mode 100755
index e9229da44..d81626e7a
--- a/dbgpt/model/proxy/llms/chatgpt.py
+++ b/dbgpt/model/proxy/llms/chatgpt.py
@@ -110,14 +110,13 @@ def _build_request(model: ProxyModel, params):
             pass
 
     # Move the last user's information to the end
-    temp_his = history[::-1]
-    last_user_input = None
-    for m in temp_his:
-        if m["role"] == "user":
-            last_user_input = m
+    last_user_input_index = None
+    for i in range(len(history) - 1, -1, -1):
+        if history[i]["role"] == "user":
+            last_user_input_index = i
             break
-    if last_user_input:
-        history.remove(last_user_input)
+    if last_user_input_index:
+        last_user_input = history.pop(last_user_input_index)
         history.append(last_user_input)
 
     payloads = {