一 查看已安装php
yum list installed | grep php

二 移除
systemctl stop php-fpm
yum -y remove php
yum -y remove php*

三 添加新的源
yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm
如果提示已安装
yum remove remi-release.noarch
yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm

四 安装
yum -y install php74
yum -y install php74-php-bcmath php74-php-cli php74-php-common php74-php-devel php74-php-embedded php74-php-fpm php74-php-gd php74-php-intl php74-php-mbstring php74-php-mysqlnd php74-php-opcache php74-php-pdo php74-php-pear php74-php-pecl-igbinary php74-php-pecl-memcached php74-php-process php74-php-xml

五 启动
systemctl restart php74-php-fpm
php74 -v