diff --git a/src/languages/MessagesConfig.js b/src/languages/MessagesConfig.js
index a7f96c9..43f314d 100644
--- a/src/languages/MessagesConfig.js
+++ b/src/languages/MessagesConfig.js
@@ -6,12 +6,14 @@ import zhCn from 'element-plus/dist/locale/zh-cn.mjs'
 import en from 'element-plus/dist/locale/en.mjs'
 import 'dayjs/locale/zh-cn'
 import dayjs from 'dayjs'
-dayjs.locale('zh-CN') // dayjs的语言配置
+
+const DEFAULT_LOCALE = 'zh-CN'
+dayjs.locale(DEFAULT_LOCALE) // dayjs的语言配置
 
 const i18n = createI18n({
-  locale: 'zh-CN', // set locale
+  locale: DEFAULT_LOCALE, // set locale
   legacy: false, // you must set `false`, to use Composition API
-  fallbackLocale: 'zh-CN', // set fallback locale
+  fallbackLocale: DEFAULT_LOCALE, // set fallback locale
   messages: {
     'zh-CN': messagesCn,
     'en-US': messagesEn
@@ -19,17 +21,13 @@ const i18n = createI18n({
 })
 
 const $currentLocale = reactive({ // 用于element-plus
-  locale: 'zh-CN',
   localeData: zhCn
 })
 
 const $changeLocale = function (locale) {
   this.$i18n.locale = locale
-  Object.assign(this.$currentLocale, {
-    locale,
-    localeData: locale === 'zh-CN' ? zhCn : en
-  })
-  dayjs.locale(locale === 'zh-CN' ? 'zh-cn' : 'en')
+  this.$currentLocale.localeData = locale === DEFAULT_LOCALE ? zhCn : en
+  dayjs.locale(locale.toLowerCase())
 }
 
 export default {