diff --git a/scripts/label_backfill.py b/scripts/label_backfill.py
index c813845..c34ea00 100644
--- a/scripts/label_backfill.py
+++ b/scripts/label_backfill.py
@@ -233,6 +233,7 @@ def main():
             total += n
             logger.info(f"本批回填 {n} 条，累计 {total} 条")
 
+        time.sleep(1)  # 限速：每批间隔1秒，减轻DB压力
         if not args.loop:
             break
         time.sleep(300)  # 5分钟