diff --git a/backend/src/module/notification/providers/bark.py b/backend/src/module/notification/providers/bark.py
index dd4e9a12..d2fe5a48 100644
--- a/backend/src/module/notification/providers/bark.py
+++ b/backend/src/module/notification/providers/bark.py
@@ -19,8 +19,7 @@ class BarkProvider(NotificationProvider):
 
     def __init__(self, config: "ProviderConfig"):
         super().__init__(config)
-        # Support both legacy token field and new device_key field
-        self.device_key = config.device_key or config.token
+        self.device_key = config.device_key
         server_url = config.server_url or self.DEFAULT_SERVER
         self.notification_url = f"{server_url.rstrip('/')}/push"
 
diff --git a/backend/src/module/notification/providers/wecom.py b/backend/src/module/notification/providers/wecom.py
index b36875ea..b995b00b 100644
--- a/backend/src/module/notification/providers/wecom.py
+++ b/backend/src/module/notification/providers/wecom.py
@@ -17,8 +17,7 @@ class WecomProvider(NotificationProvider):
 
     def __init__(self, config: "ProviderConfig"):
         super().__init__(config)
-        # Support both webhook_url and legacy chat_id field
-        self.notification_url = config.webhook_url or config.chat_id
+        self.notification_url = config.webhook_url
         self.token = config.token
 
     async def send(self, notification: Notification) -> bool:
diff --git a/backend/src/module/update/v4.py b/backend/src/module/update/v4.py
index fa312741..1cda4003 100644
--- a/backend/src/module/update/v4.py
+++ b/backend/src/module/update/v4.py
@@ -7,6 +7,8 @@
 - ``bangumi_manage.rename_method`` → ``plugins.slots.rename_strategy``
   （废弃的 ``normal`` 改为 ``none``）
 - ``bangumi_manage.revision_conflict_policy`` → ``plugins.slots.conflict_policy``
+- 通知渠道的旧字段别名：Bark 的 ``token`` → ``device_key``，WeCom 的 ``chat_id``
+  → ``webhook_url``（渠道实现不再读旧字段）
 
 在 ``Settings`` 读写配置文件之前运行。改写前把原文件备份为 ``<文件名>.v3.bak``；
 失败时从备份恢复并抛出 :class:`ConfigMigrationError`，拒绝启动。
@@ -32,6 +34,13 @@ _SLOT_FIELDS = {
 }
 
 
+# 渠道类型 → (旧字段, 新字段)；3.x 的渠道实现以 ``新字段 or 旧字段`` 读取
+_PROVIDER_ALIASES = {
+    "bark": ("token", "device_key"),
+    "wecom": ("chat_id", "webhook_url"),
+}
+
+
 class ConfigMigrationError(RuntimeError):
     """配置迁移失败；配置文件已从备份恢复。"""
 
@@ -50,6 +59,26 @@ def migrate_v3_dict(config: dict[str, Any]) -> list[str]:
 
     下载器字段合并到已有的 ``default`` 实例上，没有时新建；未出现的字段保持原样。
     """
+    return _migrate_plugin_fields(config) + _migrate_provider_aliases(config)
+
+
+def _migrate_provider_aliases(config: dict[str, Any]) -> list[str]:
+    moved = []
+    providers = _section(config, "notification").get("providers")
+    for i, provider in enumerate(providers if isinstance(providers, list) else []):
+        if not isinstance(provider, dict):
+            continue
+        old, new = _PROVIDER_ALIASES.get(
+            str(provider.get("type", "")).lower(), ("", "")
+        )
+        if old in provider:
+            legacy = provider.pop(old)
+            provider[new] = provider.get(new) or legacy
+            moved.append(f"notification.providers[{i}].{old}")
+    return moved
+
+
+def _migrate_plugin_fields(config: dict[str, Any]) -> list[str]:
     downloader = _section(config, "downloader")
     bangumi_manage = _section(config, "bangumi_manage")
     moved = [f"bangumi_manage.{key}" for key in _SLOT_FIELDS if key in bangumi_manage]
diff --git a/backend/src/test/test_update_v4.py b/backend/src/test/test_update_v4.py
index ae1c8679..950e7267 100644
--- a/backend/src/test/test_update_v4.py
+++ b/backend/src/test/test_update_v4.py
@@ -145,3 +145,55 @@ def test_migrate_v3_config_existing_backup_kept_new_backup_beside_it(v3_config):
     assert first.read_text() == "original 3.3 config"
     second = v3_config.with_name("config.json.v3.bak.1")
     assert second.read_bytes() == FIXTURE.read_bytes()
+
+
+@pytest.mark.parametrize(
+    "provider, expected",
+    [
+        # Bark 旧版把 device key 放在 token
+        ({"type": "bark", "token": "k"}, {"type": "bark", "device_key": "k"}),
+        (
+            {"type": "bark", "token": "old", "device_key": "new"},
+            {"type": "bark", "device_key": "new"},
+        ),
+        # WeCom 旧版把 webhook 地址放在 chat_id
+        (
+            {"type": "wecom", "chat_id": "https://hook", "token": "key"},
+            {"type": "wecom", "webhook_url": "https://hook", "token": "key"},
+        ),
+        (
+            {"type": "WeCom", "chat_id": "old", "webhook_url": "new"},
+            {"type": "WeCom", "webhook_url": "new"},
+        ),
+    ],
+)
+def test_migrate_v3_dict_moves_legacy_notification_aliases(provider, expected):
+    config: dict[str, Any] = {"notification": {"providers": [provider]}}
+
+    moved = migrate_v3_dict(config)
+
+    assert config["notification"]["providers"] == [expected]
+    assert len(moved) == 1 and moved[0].startswith("notification.providers[0].")
+    # 只动通知渠道：没有顺带创建 plugins 段
+    assert "plugins" not in config
+
+
+def test_migrate_v3_dict_keeps_other_providers_token_and_chat_id():
+    telegram = {"type": "telegram", "token": "t", "chat_id": "1"}
+    config: dict[str, Any] = {"notification": {"providers": [dict(telegram)]}}
+
+    assert migrate_v3_dict(config) == []
+    assert config["notification"]["providers"] == [telegram]
+
+
+def test_migrate_v3_config_rewrites_file_with_legacy_bark_token(tmp_path):
+    path = tmp_path / "config.json"
+    path.write_text(
+        json.dumps({"notification": {"providers": [{"type": "bark", "token": "k"}]}})
+    )
+
+    assert migrate_v3_config(path) is True
+
+    saved = json.loads(path.read_text())
+    assert saved["notification"]["providers"] == [{"type": "bark", "device_key": "k"}]
+    assert path.with_name("config.json.v3.bak").exists()