diff --git a/web/backend/crypto_storage.py b/web/backend/crypto_storage.py
index 9318c73..c289fd6 100644
--- a/web/backend/crypto_storage.py
+++ b/web/backend/crypto_storage.py
@@ -13,6 +13,7 @@ from Crypto.Cipher import AES
 from sqlalchemy import text
 from sqlalchemy.engine import Engine
 from sqlalchemy.types import Text, TypeDecorator
+from loguru import logger
 
 
 _PREFIX = "enc:v1:"
@@ -164,7 +165,10 @@ def _table_exists(engine: Engine, table_name: str) -> bool:
 
 
 def encrypt_existing_sensitive_data(engine: Engine) -> int:
-    """把历史明文敏感字段迁移成密文；已加密但非主密钥的值会重加密。"""
+    """把历史明文敏感字段迁移成密文；已加密但非主密钥的值会重加密。
+
+    解密失败的值（密钥丢失/变更）会被跳过并记录警告。
+    """
     primary_name = _key_candidates()[0].name
     changed = 0
 
@@ -179,7 +183,15 @@ def encrypt_existing_sensitive_data(engine: Engine) -> int:
                 raw_value = row[column_name]
                 if raw_value is None or raw_value == "":
                     continue
-                plain_value, key_name = decrypt_value_with_key_name(str(raw_value))
+                try:
+                    plain_value, key_name = decrypt_value_with_key_name(str(raw_value))
+                except ValueError:
+                    # 解密失败（密钥变更/丢失），跳过该值，避免启动阻塞
+                    logger.warning(
+                        f"跳过无法解密的字段 {table_name}.{column_name}[id={row['id']}]，"
+                        f"可能是加密密钥已变更"
+                    )
+                    continue
                 if is_encrypted(str(raw_value)) and key_name == primary_name:
                     continue
                 encrypted = encrypt_value(plain_value)