diff --git a/SubMind.py b/SubMind.py
index ab02922..6f56eec 100644
--- a/SubMind.py
+++ b/SubMind.py
@@ -289,9 +289,14 @@ async def get_subs_list_keyboard(user_id: int, category_filter: str = None) -> I
     return InlineKeyboardMarkup(keyboard)
 
 
-def _clear_action_state(context: CallbackContext, keys: list[str]):
-    for key in keys:
-        context.user_data.pop(key, None)
+def _get_new_sub_data_or_end(update: Update, context: CallbackContext):
+    sub_data = context.user_data.get('new_sub_data')
+    if sub_data is None:
+        message_obj = update.message or (update.callback_query.message if update.callback_query else None)
+        if message_obj:
+            # 统一提示，避免 KeyError 导致会话崩溃
+            return None, message_obj
+    return sub_data, None
 
 
 # --- 自动任务 ---
@@ -608,6 +613,12 @@ async def add_sub_start(update: Update, context: CallbackContext):
 
 
 async def add_name_received(update: Update, context: CallbackContext):
+    sub_data, err_msg_obj = _get_new_sub_data_or_end(update, context)
+    if sub_data is None:
+        if err_msg_obj:
+            await err_msg_obj.reply_text("会话已过期，请重新使用 /add_sub 开始。")
+        return ConversationHandler.END
+
     name = update.message.text.strip()
     if not name:
         await update.message.reply_text("订阅名称不能为空。")
@@ -615,17 +626,23 @@ async def add_name_received(update: Update, context: CallbackContext):
     if len(name) > MAX_NAME_LEN:
         await update.message.reply_text(f"订阅名称过长，请控制在 {MAX_NAME_LEN} 个字符以内。")
         return ADD_NAME
-    context.user_data['new_sub_data']['name'] = name
+    sub_data['name'] = name
     await update.message.reply_text("第二步：请输入订阅 *费用*", parse_mode='MarkdownV2')
     return ADD_COST
 
 
 async def add_cost_received(update: Update, context: CallbackContext):
+    sub_data, err_msg_obj = _get_new_sub_data_or_end(update, context)
+    if sub_data is None:
+        if err_msg_obj:
+            await err_msg_obj.reply_text("会话已过期，请重新使用 /add_sub 开始。")
+        return ConversationHandler.END
+
     try:
         cost = float(update.message.text)
         if cost < 0:
             raise ValueError("费用不能为负数")
-        context.user_data['new_sub_data']['cost'] = cost
+        sub_data['cost'] = cost
     except (ValueError, TypeError):
         await update.message.reply_text("费用必须是有效的非负数字。")
         return ADD_COST
@@ -634,16 +651,28 @@ async def add_cost_received(update: Update, context: CallbackContext):
 
 
 async def add_currency_received(update: Update, context: CallbackContext):
+    sub_data, err_msg_obj = _get_new_sub_data_or_end(update, context)
+    if sub_data is None:
+        if err_msg_obj:
+            await err_msg_obj.reply_text("会话已过期，请重新使用 /add_sub 开始。")
+        return ConversationHandler.END
+
     currency = update.message.text.upper()
     if not (len(currency) == 3 and currency.isalpha()):
         await update.message.reply_text("请输入有效的三字母货币代码（如 USD, CNY）。")
         return ADD_CURRENCY
-    context.user_data['new_sub_data']['currency'] = currency
+    sub_data['currency'] = currency
     await update.message.reply_text("第四步：请为订阅指定一个 *类别*", parse_mode='MarkdownV2')
     return ADD_CATEGORY
 
 
 async def add_category_received(update: Update, context: CallbackContext):
+    sub_data, err_msg_obj = _get_new_sub_data_or_end(update, context)
+    if sub_data is None:
+        if err_msg_obj:
+            await err_msg_obj.reply_text("会话已过期，请重新使用 /add_sub 开始。")
+        return ConversationHandler.END
+
     user_id, category_name = update.effective_user.id, update.message.text.strip()
     if not category_name:
         await update.message.reply_text("类别不能为空。")
@@ -651,7 +680,7 @@ async def add_category_received(update: Update, context: CallbackContext):
     if len(category_name) > MAX_CATEGORY_LEN:
         await update.message.reply_text(f"类别名称过长，请控制在 {MAX_CATEGORY_LEN} 个字符以内。")
         return ADD_CATEGORY
-    context.user_data['new_sub_data']['category'] = category_name
+    sub_data['category'] = category_name
     with get_db_connection() as conn:
         cursor = conn.cursor()
         cursor.execute("INSERT OR IGNORE INTO categories (user_id, name) VALUES (?, ?)", (user_id, category_name))
@@ -662,11 +691,17 @@ async def add_category_received(update: Update, context: CallbackContext):
 
 
 async def add_next_due_received(update: Update, context: CallbackContext):
+    sub_data, err_msg_obj = _get_new_sub_data_or_end(update, context)
+    if sub_data is None:
+        if err_msg_obj:
+            await err_msg_obj.reply_text("会话已过期，请重新使用 /add_sub 开始。")
+        return ConversationHandler.END
+
     parsed_date = parse_date(update.message.text)
     if not parsed_date:
         await update.message.reply_text("无法识别的日期格式，请使用类似 '2025\\-10\\-01' 或 '10月1日' 的格式。")
         return ADD_NEXT_DUE
-    context.user_data['new_sub_data']['next_due'] = parsed_date
+    sub_data['next_due'] = parsed_date
     keyboard = [
         [InlineKeyboardButton("天", callback_data='freq_unit_day'),
          InlineKeyboardButton("周", callback_data='freq_unit_week')],
@@ -679,23 +714,34 @@ async def add_next_due_received(update: Update, context: CallbackContext):
 
 
 async def add_freq_unit_received(update: Update, context: CallbackContext):
+    sub_data, _ = _get_new_sub_data_or_end(update, context)
     query = update.callback_query
     await query.answer()
+    if sub_data is None:
+        await query.edit_message_text("会话已过期，请重新使用 /add_sub 开始。")
+        return ConversationHandler.END
+
     unit = query.data.split('_')[2]
     if unit not in VALID_FREQ_UNITS:
         await query.edit_message_text("错误：无效的周期单位，请重试。")
         return ConversationHandler.END
-    context.user_data['new_sub_data']['unit'] = unit
+    sub_data['unit'] = unit
     await query.edit_message_text("第七步：请输入周期的*数量*（例如：每3个月，输入 3）", parse_mode='Markdown')
     return ADD_FREQ_VALUE
 
 
 async def add_freq_value_received(update: Update, context: CallbackContext):
+    sub_data, err_msg_obj = _get_new_sub_data_or_end(update, context)
+    if sub_data is None:
+        if err_msg_obj:
+            await err_msg_obj.reply_text("会话已过期，请重新使用 /add_sub 开始。")
+        return ConversationHandler.END
+
     try:
         value = int(update.message.text)
         if value <= 0:
             raise ValueError
-        context.user_data['new_sub_data']['value'] = value
+        sub_data['value'] = value
     except (ValueError, TypeError):
         await update.message.reply_text("请输入一个有效的正整数。")
         return ADD_FREQ_VALUE
@@ -709,13 +755,18 @@ async def add_freq_value_received(update: Update, context: CallbackContext):
 
 
 async def add_renewal_type_received(update: Update, context: CallbackContext):
+    sub_data, _ = _get_new_sub_data_or_end(update, context)
     query = update.callback_query
     await query.answer()
+    if sub_data is None:
+        await query.edit_message_text("会话已过期，请重新使用 /add_sub 开始。")
+        return ConversationHandler.END
+
     renewal_type = query.data.split('_')[1]
     if renewal_type not in VALID_RENEWAL_TYPES:
         await query.edit_message_text("错误：无效的续费类型，请重试。")
         return ConversationHandler.END
-    context.user_data['new_sub_data']['renewal_type'] = renewal_type
+    sub_data['renewal_type'] = renewal_type
     await query.edit_message_text("最后一步（可选）：需要添加备注吗？\n（如：共享账号、用途等。不需要请 /skip）")
     return ADD_NOTES