composer下载：

"require": {
    "qcloud/cos-sdk-v5": ">=2.0"
}

composer安装

php composer.phar install

修改 config/filesystem.php 

 'disks'   => [
        'local'  => [
            'type' => 'local',
            'root' => app()->getRootPath() . 'storage'
        ]

public function fileupload(Request $request)
    {
        $file=$request->file("file");
        $savename = \think\facade\Filesystem::putFile( 'topic', $file);
        $data=Cos::getCos($savename);
        return json(['error_code'=>0,'data'=>$data,'msg'=>'ok']);
    }

server/Cos.php

<?php
namespace app\api\server;
use app\Request;
use Qcloud\Cos\Client;
 
class Cos
{
    public static function getCos($savename)
    {
        //腾讯云cos
        $secretId = ""; //"云 API 密钥 SecretId";
        $secretKey = ""; //"云 API 密钥 SecretKey";
        $region = "ap-shanghai"; //设置一个默认的存储桶地域
        $cosClient = new Client(
            array(
                'region' => $region,
                'schema' => 'https', //协议头部，默认为http
                'credentials' => array(
                    'secretId' => $secretId,
                    'secretKey' => $secretKey)
            )
        );
        //设置一个对象键(尽量不包含特殊符号)
        $keyv = rand(0,99999999);
        # 上传文件
        ### 上传文件流
        try {
            $bucket = ""; //存储桶名称 格式：BucketName-APPID
            $key = $keyv; //此处的 key 为对象键，对象键是对象在存储桶中的唯一标识
            $srcPath = 'D:\phpstudy_pro\WWW\picurlstorage/'.$savename;//本地文件绝对路径
            $file = fopen($srcPath,'rb');
            if ($file) {
                $cosClient->Upload(
                    $bucket = $bucket,
                    $key = $key,
                    $body = $file
                );
            }
        } catch (\Exception $e) {
            return $e;
        }
 
        //拼接存储路径
        $path = '网址'.$key;
 
        return $path;
 
    }

 全程粘就好