diff --git a/vitepress-docs/docs/en/cli.md b/vitepress-docs/docs/en/cli.md
index f732d680..ed0a0144 100644
--- a/vitepress-docs/docs/en/cli.md
+++ b/vitepress-docs/docs/en/cli.md
@@ -74,6 +74,7 @@ compatibility_flags = [ "nodejs_compat" ]
 # ]
 
 [vars]
+# DEFAULT_LANG = "zh"
 # TITLE = "Custom Title" # The title of the site
 PREFIX = "tmp" # The mailbox name prefix to be processed
 # (min, max) length of the adderss, if not set, the default is (1, 30)
diff --git a/vitepress-docs/docs/zh/guide/worker-vars.md b/vitepress-docs/docs/zh/guide/worker-vars.md
index 89fd5979..bd9a8c25 100644
--- a/vitepress-docs/docs/zh/guide/worker-vars.md
+++ b/vitepress-docs/docs/zh/guide/worker-vars.md
@@ -90,6 +90,7 @@
 
 | 变量名                    | 类型        | 说明                                             | 示例                  |
 | ------------------------- | ----------- | ------------------------------------------------ | --------------------- |
+| `DEFAULT_LANG`            | 文本        | Worker 错误信息默认语言, zh/en                   | `zh`                  |
 | `TITLE`                   | 文本        | 自定义前端页面网站标题，支持 html                | `Custom Title`        |
 | `ANNOUNCEMENT`            | 文本        | 自定义前端页面公告，支持 html                    | `Custom Announcement` |
 | `COPYRIGHT`               | 文本        | 自定义前端界面页脚文本，支持 html                | `Dream Hunter`        |
diff --git a/worker/src/admin_api/worker_config.ts b/worker/src/admin_api/worker_config.ts
index 8d4d3b48..7bfa5acb 100644
--- a/worker/src/admin_api/worker_config.ts
+++ b/worker/src/admin_api/worker_config.ts
@@ -8,6 +8,7 @@ import { isS3Enabled } from '../mails_api/s3_attachment';
 export default {
     getConfig: async (c: Context<HonoCustomType>) => {
         return c.json({
+            "DEFAULT_LANG": c.env.DEFAULT_LANG,
             "TITLE": c.env.TITLE,
             "HAS_PASSWORD": getPasswords(c).length,
             "HAS_ADMIN_PASSWORDS": getAdminPasswords(c).length,
diff --git a/worker/wrangler.toml.template b/worker/wrangler.toml.template
index 113ef61e..ff01b7ab 100644
--- a/worker/wrangler.toml.template
+++ b/worker/wrangler.toml.template
@@ -16,6 +16,7 @@ compatibility_flags = [ "nodejs_compat" ]
 # ]
 
 [vars]
+# DEFAULT_LANG = "zh"
 # TITLE = "Custom Title" # custom title
 # ANNOUNCEMENT = "Custom Announcement"
 PREFIX = "tmp"