修改源，默认源找不到包

rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
rpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm

安装，如果有其他扩展要加上也可以加一起，如果要执行安装目录可以加上 --installroot=/usr/local

yum -y install php72w php72w-cli php72w-fpm php72w-common php72w-devel

启动服务

systemctl enable php-fpm.service
systemctl start php-fpm.service