查看yum有没有被启用的仓库:yum repolist all 没有启用的仓库,就需要更换新的镜像,备份并下载新的镜像: cd /etc/yum.repos.d mkdir bak mv *.repo bak wget http://mirrors.aliyun.com/repo/Centos-8.repo yum clean all yum makecache