diff --git a/nonebot_plugin_llmchat/__init__.py b/nonebot_plugin_llmchat/__init__.py
index 624da69..aa39a7c 100755
--- a/nonebot_plugin_llmchat/__init__.py
+++ b/nonebot_plugin_llmchat/__init__.py
@@ -39,7 +39,10 @@ require("nonebot_plugin_apscheduler")
 from nonebot_plugin_apscheduler import scheduler
 
 require("nonebot_plugin_tortoise_orm")
-from nonebot_plugin_tortoise_orm import init_orm_plugin
+# 必须在 require 之后导入模型，才能正确注册到 Tortoise ORM
+from . import models  # noqa: F401
+
+require("nonebot_plugin_tortoise_orm")
 
 if TYPE_CHECKING:
     from openai.types.chat import (
@@ -49,7 +52,6 @@ if TYPE_CHECKING:
 
 from .db_manager import DatabaseManager
 from .models import ChatHistory, ChatMessage, GroupChatState, PrivateChatState
-from .migration import backup_json_files, migrate_from_json_to_db
 
 __plugin_meta__ = PluginMetadata(
     name="llmchat",
@@ -644,11 +646,13 @@ async def handle_reset(event: GroupMessageEvent | PrivateMessageEvent, args: Mes
     if isinstance(event, GroupMessageEvent):
         context_id = event.group_id
         state = group_states[context_id]
+        await DatabaseManager.clear_group_history(context_id)
     else:  # PrivateMessageEvent
         if not plugin_config.enable_private_chat:
             return
         context_id = event.user_id
         state = private_chat_states[context_id]
+        await DatabaseManager.clear_private_history(context_id)
 
     state.past_events.clear()
     state.history.clear()
@@ -774,25 +778,9 @@ async def load_state():
 @driver.on_startup
 async def init_plugin():
     logger.info("插件启动初始化")
-    # 初始化 Tortoise ORM 的模型
-    await init_orm_plugin()
-    # 创建表（如果不存在）
-    try:
-        # Tortoise ORM 会自动创建表，这里只是尝试检查
-        logger.info("数据库表初始化中...")
-    except Exception as e:
-        logger.warning(f"初始化数据库时出现警告: {e}")
-    
-    # 执行迁移（从 JSON 到数据库）
-    try:
-        await migrate_from_json_to_db(plugin_config)
-    except Exception as e:
-        logger.warning(f"执行迁移时出现错误: {e}")
-    
     await load_state()
     # 每5分钟保存状态
     scheduler.add_job(save_state, "interval", minutes=5)
-    
     logger.info("插件初始化完成")
 
 
diff --git a/nonebot_plugin_llmchat/db_manager.py b/nonebot_plugin_llmchat/db_manager.py
index af042b7..f2411e0 100644
--- a/nonebot_plugin_llmchat/db_manager.py
+++ b/nonebot_plugin_llmchat/db_manager.py
@@ -8,7 +8,6 @@ from datetime import datetime
 from typing import Optional
 
 from nonebot import logger
-from tortoise.exceptions import DoesNotExist
 
 from .models import ChatHistory, ChatMessage, GroupChatState, PrivateChatState
 
@@ -25,7 +24,7 @@ class DatabaseManager:
         output_reasoning_content: bool,
         random_trigger_prob: float,
     ):
-        """保存群组状态和历史到数据库"""
+        """保存群组状态"""
         try:
             # 保存或更新群组状态
             state, _ = await GroupChatState.get_or_create(
@@ -72,7 +71,7 @@ class DatabaseManager:
         user_prompt: Optional[str],
         output_reasoning_content: bool,
     ):
-        """保存私聊状态和历史到数据库"""
+        """保存私聊状态"""
         try:
             # 保存或更新私聊状态
             state, _ = await PrivateChatState.get_or_create(
@@ -110,7 +109,7 @@ class DatabaseManager:
             logger.error(f"保存私聊状态失败 用户: {user_id}, 错误: {e}")
 
     @staticmethod
-    async def load_group_state(group_id: int, history_maxlen: int) -> dict:
+    async def load_group_state(group_id: int, history_maxlen: int) -> Optional[dict]:
         """从数据库加载群组状态"""
         try:
             state = await GroupChatState.get_or_none(group_id=group_id)
@@ -145,7 +144,7 @@ class DatabaseManager:
             return None
 
     @staticmethod
-    async def load_private_state(user_id: int, history_maxlen: int) -> dict:
+    async def load_private_state(user_id: int, history_maxlen: int) -> Optional[dict]:
         """从数据库加载私聊状态"""
         try:
             state = await PrivateChatState.get_or_none(user_id=user_id)
diff --git a/nonebot_plugin_llmchat/models.py b/nonebot_plugin_llmchat/models.py
index 51e2c9e..d6b17dd 100644
--- a/nonebot_plugin_llmchat/models.py
+++ b/nonebot_plugin_llmchat/models.py
@@ -3,12 +3,14 @@ Tortoise ORM 模型定义
 用于存储聊天历史和群组/私聊状态
 """
 import json
-from datetime import datetime
-from typing import Optional
 
+from nonebot_plugin_tortoise_orm import add_model
 from tortoise import fields
 from tortoise.models import Model
 
+# 注册模型到 Tortoise ORM
+add_model(__name__)
+
 
 class GroupChatState(Model):
     """群组聊天状态"""
@@ -24,7 +26,7 @@ class GroupChatState(Model):
 
     class Meta:
         table = "llmchat_group_state"
-        description = "群组聊天状态表"
+        table_description = "群组聊天状态表"
 
 
 class PrivateChatState(Model):
@@ -40,7 +42,7 @@ class PrivateChatState(Model):
 
     class Meta:
         table = "llmchat_private_state"
-        description = "私聊状态表"
+        table_description = "私聊状态表"
 
 
 class ChatMessage(Model):
@@ -59,11 +61,7 @@ class ChatMessage(Model):
 
     class Meta:
         table = "llmchat_message"
-        description = "聊天消息历史表"
-        indexes = [
-            ("group_id", "is_private", "created_at"),  # 复合索引用于快速查询
-            ("user_id", "is_private", "created_at"),
-        ]
+        table_description = "聊天消息历史表"
 
     @staticmethod
     def serialize_content(content) -> str:
@@ -89,7 +87,7 @@ class ChatHistory(Model):
 
     class Meta:
         table = "llmchat_history"
-        description = "聊天历史快照表（用于快速加载）"
+        table_description = "聊天历史快照表（用于快速加载）"
 
     @staticmethod
     def serialize_messages(messages_list) -> str: