composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/ (阿里云)
或
composer config -g repo.packagist composer https://packagist.phpcomposer.com
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/ (阿里云)
或
composer config -g repo.packagist composer https://packagist.phpcomposer.com