检查是否安装完成
composer --version composer -V 注意这里要大写 composer -vvv 命令查看更详细的信息，及帮助。
全局配置（推荐）镜像
阿里云 composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/ 华为云 composer config -g repo.packagist composer https://mirrors.huaweicloud.com/repository/php/ 腾讯云 composer config -g repos.packagist composer https://mirrors.cloud.tencent.com/composer/ phpcomposer Composer官方镜像（速度慢的一匹） composer config -g repo.packagist composer https://packagist.phpcomposer.com Packagist 中国全量镜像（由安畅网络赞助） composer config -g repo.packagist composer https://php.cnpkg.org Packagist / JP 日本镜像（一个日本开发者搭建的镜像） composer config -g repo.packagist composer https://packagist.mirrors.sjtug.sjtu.edu.cn/ Packagist Mirror 上海交通大学镜像 composer config -g repo.packagist composer https://packagist.mirrors.sjtug.sjtu.edu.cn/ 恢复原版镜像 composer config -g --unset repos.packagist
降低版本：
降到指定版本 composer self-update 1.4.1 降到 1版本 composer self-update --1
更新：
composer update
