1、cd 到yum原始檔所在位置
cd /etc/yum.repos.d
2、備份CentOS-Base.repo原始檔
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
3、下載阿里雲yum源配置檔案
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
4、清理yum快取
yum clean all
5、生成新的快取
yum makecache
6、更新yum源
yum update
借鑑文章地址：https://blog.csdn.net/qq_52545155/article/details/137229782