mv /etc/yum.repos.d/CentOS-base.repo /etc/yum.repos.d/CentOS-base.repo.backup
wget -O /etc/yum.repos.d/CentOS-base.repo http://mirrors.cloud.tencent.com/repo/centos8_base.repo
sed -i -e "s|mirrorlist=|#mirrorlist=|g" /etc/yum.repos.d/CentOS-*
sed -i -e "s|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g" /etc/yum.repos.d/CentOS-*
yum clean all
yum makecache