1. 首先要安装wget `[root@localhost ~]# yum -y install wget` 1. 备份 旧的yum源 `[root@localhost ~]# mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo_bak` 1. 下载新的yum源 `[root@localhost ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo` 1. 更新 ` [root@localhost ~]# yum makecache` ` [root@localhost ~]# yum -y update`