diff --git a/_keyword_scorer.py b/_keyword_scorer.py
index e44bb03..228b83f 100644
--- a/_keyword_scorer.py
+++ b/_keyword_scorer.py
@@ -56,6 +56,38 @@ class KeywordScorer:
             conn.close()
         logger.debug(f"[keyword-scorer] DB初始化完成: {self.db_path}")
 
+    def _ensure_keyword_scores_table(self):
+        """确保keyword_scores表存在（防御性编程）"""
+        conn = sqlite3.connect(self.db_path, check_same_thread=False)
+        try:
+            cursor = conn.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='keyword_scores'")
+            if not cursor.fetchone():
+                logger.warning("[keyword-scorer] keyword_scores表不存在，重新创建")
+                conn.execute("""
+                    CREATE TABLE IF NOT EXISTS keyword_scores (
+                        id INTEGER PRIMARY KEY AUTOINCREMENT,
+                        platform TEXT NOT NULL,
+                        message_text TEXT NOT NULL,
+                        message_hash TEXT NOT NULL,
+                        score INTEGER NOT NULL DEFAULT 0,
+                        matched_keywords TEXT NOT NULL DEFAULT '',
+                        local_time TIMESTAMP NOT NULL,
+                        is_new_message INTEGER NOT NULL DEFAULT 1
+                    )
+                """)
+                conn.execute("""
+                    CREATE INDEX IF NOT EXISTS idx_keyword_scores_platform_time
+                    ON keyword_scores(platform, local_time)
+                """)
+                conn.execute("""
+                    CREATE INDEX IF NOT EXISTS idx_keyword_scores_hash
+                    ON keyword_scores(message_hash)
+                """)
+                conn.commit()
+                logger.warning("[keyword-scorer] keyword_scores表已重新创建")
+        finally:
+            conn.close()
+
     def extract_keywords(self, text: str) -> List[str]:
         """提取两字一组的关键词
 
@@ -110,6 +142,9 @@ class KeywordScorer:
         if not keywords:
             return 0, []
 
+        # 防御性编程：确保表存在
+        self._ensure_keyword_scores_table()
+
         conn = sqlite3.connect(self.db_path, check_same_thread=False)
         try:
             # 获取最近N分钟的bot回复关键词
@@ -168,6 +203,9 @@ class KeywordScorer:
             matched_keywords: 匹配到的关键词
             is_new: 是否为新消息（score<=1为True）
         """
+        # 防御性编程：确保表存在
+        self._ensure_keyword_scores_table()
+
         import hashlib
         message_hash = hashlib.md5(message_text.strip().encode('utf-8')).hexdigest()
         local_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
@@ -192,6 +230,8 @@ class KeywordScorer:
         keywords = self.extract_keywords(text)
         if not keywords:
             return 0
+        # 防御性编程：确保表存在
+        self._ensure_keyword_scores_table()
         conn = sqlite3.connect(self.db_path, check_same_thread=False)
         try:
             cursor = conn.execute("""
@@ -272,6 +312,9 @@ class KeywordScorer:
 
         exclude_id: 排除刚插入的当前消息记录id（防止自拦截）
         """
+        # 防御性编程：确保表存在
+        self._ensure_keyword_scores_table()
+
         import hashlib
         from datetime import timedelta