首先使用composer安装类库

composer require mews/captcha

注册provider

'providers' => [
        // ...
        Mews\Captcha\CaptchaServiceProvider::class,
    ]
'aliases' => [
        // ...
        'Captcha' => 'Mews\Captcha\Facades\Captcha',
    ]

生存相应配置文件
php artisan vendor:publish
可以自定义自己的验证码样式，具体代码，请参照官方文档
Captcha.config 文件下
'login'    => [
        'length'    => 4,
        'width'     => 80,
        'height'    => 30,
        'quality'   => 90,
        'lines'     => 6,
        'bgImage'   => false,
        'bgColor'   => '#ecf2f4',
        'fontColors'=> ['#2c3e50', '#c0392b', '#16a085', '#c0392b', '#8e44ad', '#303f9f', '#f57c00', '#795548'],
        'contrast'  => -5,
        'angle'     => 15,
    ]

创建相关验证码路由

//-----------------通用-验证码-------------------//
Route::get('create_code',['uses' => 'VerifyController@create_code','as' => 'create_code']);
Route::post('check_code',['uses' => 'VerifyController@check_code','as' => 'check_code']);

相应控制器

<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use Mews\Captcha\Facades\Captcha;
class VerifyController extends Controller{
    public function create_code(){
        return Captcha::create('login');
    }
    /**用于验证验证码**/
    public function check_code(Request $request){
        $validator = Captcha::check($request->input('verify'));
        return response()->json($validator);
    }
}

前台页面

<div class="form-code-img pull-left">
<img src="{{ route('create_code') }}" alt="" id="verify"  name="login_code" onclick="this.src='{{ route('create_code') }}?r='+Math.random();" title="点击刷新">
</div>