/config/filesystem.php添加代码：

        // 更多的磁盘配置信息
        'images' => [
            // 磁盘类型
            'type'       => 'local',
            // 磁盘路径
            'root'       => app()->getRootPath() . 'public/uploads',
            // 磁盘路径对应的外部URL路径
            'url'        => '/uploads',
            // 可见性
            'visibility' => 'public',
        ],

后端：

$file = request() -> file('file');
$temp = explode(".", $_FILES["file"]["name"]);
$extension = end($temp);
if(!in_array($extension, array("gif","jpeg","jpg","png"))){
	$this->error('上传图片不合法！');
}
$saveName = \think\facade\Filesystem::disk('images') -> putFile('images', $file, 'uniqid');
$pic = str_replace('\\', '/', '/uploads/' . $saveName);
//$pic上传后地址：/uploads/images/5fdcc92d9e267.png