直接使用如下命令进行指定版本安装
yum -y install php71w php71w-cli php71w-devel php71w-embedded php71w-fpm php71w-gd php71w-mbstring php71w-mysqlnd php71w-opcache php71w-pdo php71w-xml php71w-mcrypt php71w-process php71w-odbc php71w-phpdbg php71w-opcache php71w-mcrypt php71w-common
yum install 指定安装php版本，错误：php71w-common conflicts with php-common-5.4.16-46.1.el7_7.x86_64本