环境：centos 7.4
只搭建阿里源
步骤一：安装wget，已安装则跳过此步骤
[root@localhost ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
-bash: wget: 未找到命令
[root@localhost yum.repos.d]# yum -y install wget
步骤二：移除旧YUM源
[root@localhost ~]# mkdir -p /etc/yum.repos.d/bak && mv /etc/yum.repos.d/* /etc/yum.repos.d/bak mv: 无法将目录"/etc/yum.repos.d/bak" 移动至自身的子目录"/etc/yum.repos.d/bak/bak" 下
步骤三：下载阿里源配置
[root@localhost ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo [root@localhost ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
步骤四：清楚缓存，查看YUM源
[root@localhost ~]# yum clean all
[root@localhost ~]# yum repolist
原文：https://www.cnblogs.com/wangzy-tongq/p/12800758.html