使用yii\filters下的比如\PageCache需要在web.php里面的组件上配置'cache' => [ 'class' => 'yii\caching\FileCache', ],

public function behaviors()
{
    /*需要在config文件下的web.php里面加上
    'cache' => [
    'class' => 'yii\caching\FileCache',
    ],*/
    return [
        [
            'class' => 'yii\filters\PageCache',
            'only' => ['index'],
            'duration' => 60,
            'variations' => [
                \Yii::$app->language,
            ],
            'dependency' => [
                'class' => 'yii\caching\DbDependency',
                'sql' => 'SELECT COUNT(*) FROM miaosha',
            ],
        ],
    ];
}