Laravel5.6 使用手动认证 auth，Auth::check () 总是验证不了

laravel5.6 使用手动认证auth，Auth::check()总是验证不了：
这是我的auth.php配置文件：

'defaults' => [
        'guard' => 'admin',
        'passwords' => 'users',
    ],
    'guards' => [
        'admin' => [
            'driver' => 'session',
            'provider' => 'users',
        ],
        'api' => [
            'driver' => 'token',
            'provider' => 'users',
        ],
    ],
    'providers' => [
        'users' => [
            'driver' => 'eloquent',
            'model' => App\Models\Admin\User::class,
            //'model' => 'App\Models\Admin\User',
        ],
    // 'users' => [
    //     'driver' => 'database',
    //     'table' => 'users',
    // ],
    ],

这个是我的登录验证类：

<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;

class LoginController extends Controller {

    /**
     * 处理身份认证
     * @return Response
     */
    public function authenticate(Request $request) {
        $username = $request->has('username') ? $request->input('username') : '';
        $password = $request->has('password') ? $request->input('password') : '';
        if (Auth::attempt(['account' => $username, 'password' => $password])) {
            return redirect('/admin/index');
        } else {
            return redirect('/admin/login')->with('error', '账号或密码错误');
        }
    }

}

这个是我的basecontroller里面的验证组件：

<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;

class BaseController extends Controller {

    public function __construct() {
        $this->middleware('auth', ['except' => ['login', 'logout']]);
    }

    public function getValue(Request $request, $key) {
        $data = $request->has($key) ? $request->input($key) : '';
        return $data;
    }

}

登录成功后跳转到admin/index ，AdminController类继承basecontroller类，但是跳转到admin/index的时候，总是验证失败，使用Auth::check()也总是返回false，在checklogin的时候是成功的，下面这里是成功的，

  if (Auth::attempt(['account' => $username, 'password' => $password])) {
            return redirect('/admin/index');
        } 

哪位大神能给指点下，是不是哪里配置错了？ 谢谢。