共三步：

1、新建中间件：

php artisan make:middleware EnableCrossRequestMiddleware

2、EnableCrossRequestMiddleware.php中重写中间件里面的内容：

<?php
namespace App\Http\Middleware;
use Closure;
class EnableCrossRequestMiddleware
{/*** Handle an incoming request.** @param  \Illuminate\Http\Request $request* @param  \Closure $next* @return mixed*/public function handle($request, Closure $next){$response = $next($request);$response->header('Access-Control-Allow-Origin', '*');$response->header('Access-Control-Allow-Headers', 'Origin, Content-Type, Cookie, Accept');$response->header('Access-Control-Allow-Methods', 'GET, POST, PATCH, PUT, OPTIONS,DELETE');$response->header('Access-Control-Allow-Credentials', 'false');return $response;}
}

3、在Kernel.php中 注册中间件：

\App\Http\Middleware\EnableCrossRequestMiddleware::class,