diff --git a/.changeset/modern-keys-spend.md b/.changeset/modern-keys-spend.md
new file mode 100644
index 0000000000..551b310e7d
--- /dev/null
+++ b/.changeset/modern-keys-spend.md
@@ -0,0 +1,5 @@
+---
+"@lynx-js/rspeedy": patch
+---
+
+Support cli flag `--base` to specify the base path of the server.
diff --git a/packages/rspeedy/core/src/cli/commands.ts b/packages/rspeedy/core/src/cli/commands.ts
index ac01178830..be7432ac5f 100644
--- a/packages/rspeedy/core/src/cli/commands.ts
+++ b/packages/rspeedy/core/src/cli/commands.ts
@@ -53,6 +53,7 @@ export function apply(program: Command): Command {
     .description(
       'Run the dev server and watch for source file changes while serving.',
     )
+    .option('--base <base>', 'specify the base path of the server')
     .action(
       (devOptions: DevOptions) =>
         import('./dev.js').then(({ dev }) =>
@@ -75,6 +76,7 @@ export function apply(program: Command): Command {
   const previewCommand = program.command('preview')
   previewCommand
     .description('Preview the production build outputs locally.')
+    .option('--base <base>', 'specify the base path of the server')
     .action((previewOptions: PreviewOptions) =>
       import('./preview.js').then(({ preview }) =>
         preview.call(previewCommand, cwd, previewOptions)
diff --git a/packages/rspeedy/core/src/cli/dev.ts b/packages/rspeedy/core/src/cli/dev.ts
index 91f1a79d2f..d85626922d 100644
--- a/packages/rspeedy/core/src/cli/dev.ts
+++ b/packages/rspeedy/core/src/cli/dev.ts
@@ -13,7 +13,9 @@ import { loadConfig, resolveConfigPath } from '../config/loadConfig.js'
 import { createRspeedy } from '../create-rspeedy.js'
 import { exit } from './exit.js'
 
-export type DevOptions = CommonOptions
+export interface DevOptions extends CommonOptions {
+  base?: string | undefined
+}
 
 export async function dev(
   this: Command,
@@ -29,6 +31,11 @@ export async function dev(
       configPath,
     })
 
+    if (devOptions.base) {
+      rspeedyConfig.server ??= {}
+      rspeedyConfig.server.base = devOptions.base
+    }
+
     const watchedFiles = [configPath]
 
     if (Array.isArray(rspeedyConfig.dev?.watchFiles)) {
diff --git a/packages/rspeedy/core/src/cli/preview.ts b/packages/rspeedy/core/src/cli/preview.ts
index 24951f4193..7a3cb3a54d 100644
--- a/packages/rspeedy/core/src/cli/preview.ts
+++ b/packages/rspeedy/core/src/cli/preview.ts
@@ -9,22 +9,31 @@ import color from 'picocolors'
 
 import type { CommonOptions } from './commands.js'
 import { exit } from './exit.js'
-import { loadConfig } from '../config/loadConfig.js'
+import { loadConfig, resolveConfigPath } from '../config/loadConfig.js'
 import { createRspeedy } from '../create-rspeedy.js'
 
-export type PreviewOptions = CommonOptions
+export interface PreviewOptions extends CommonOptions {
+  base?: string | undefined
+}
 
 export async function preview(
   this: Command,
   cwd: string,
-  options: PreviewOptions,
+  previewOptions: PreviewOptions,
 ): Promise<void> {
   try {
+    const configPath = resolveConfigPath(cwd, previewOptions.config)
+
     const { content: rspeedyConfig } = await loadConfig({
       cwd,
-      configPath: options.config,
+      configPath,
     })
 
+    if (previewOptions.base) {
+      rspeedyConfig.server ??= {}
+      rspeedyConfig.server.base = previewOptions.base
+    }
+
     const rspeedy = await createRspeedy({ cwd, rspeedyConfig })
 
     await rspeedy.initConfigs()
diff --git a/website/docs/en/guide/cli.md b/website/docs/en/guide/cli.md
index 08b171715e..31687de2dd 100644
--- a/website/docs/en/guide/cli.md
+++ b/website/docs/en/guide/cli.md
@@ -64,6 +64,7 @@ The `rspeedy dev` command is used to start a local dev server and compile the so
 Usage: rspeedy dev [options]
 
 Options:
+  -b --base <base>      specify the base path of the server
   -c --config <config>  specify the configuration file, can be a relative or absolute path
   -h, --help            display help for command
 ```
@@ -94,6 +95,7 @@ The `rspeedy preview` command is used to preview the production build outputs lo
 Usage: rspeedy preview [options]
 
 Options:
+  -b --base <base>      specify the base path of the server
   -c --config <config>  specify the configuration file, can be a relative or absolute path
   -h, --help            display help for command
 ```
diff --git a/website/docs/zh/guide/cli.md b/website/docs/zh/guide/cli.md
index 8f1d99d1fe..aee1e7d5ee 100644
--- a/website/docs/zh/guide/cli.md
+++ b/website/docs/zh/guide/cli.md
@@ -64,6 +64,7 @@ Commands:
 Usage: rspeedy dev [options]
 
 Options:
+  -b --base <base>      specify the base path of the server
   -c --config <config>  specify the configuration file, can be a relative or absolute path
   -h, --help            display help for command
 ```
@@ -94,6 +95,7 @@ Options:
 Usage: rspeedy preview [options]
 
 Options:
+  -b --base <base>      specify the base path of the server
   -c --config <config>  specify the configuration file, can be a relative or absolute path
   -h, --help            display help for command
 ```