1、php -v 
PHP 5.4.16 (cli) (built: Nov 6 2016 00:29:02) 
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2013 Zend Technologies

2、執行下面的命令升級軟件倉庫 
rpm -Uvh https://mirror.webtatic.com/yum/el7/epel-release.rpm 
rpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm

3、執行下面的命令刪除php 
yum remove php-common 
然後像安裝那樣問你是否繼續的，輸入yes即可

yum list installed | grep php 
yum remove php56w.x86_64 
yum remove ....

4、安裝php 5.6版本
yum install -y php56w php56w-opcache php56w-xml php56w-mcrypt php56w-gd php56w-devel php56w-mysql php56w-intl php56w-mbstring

5、安裝PHP FPM
yum install php56w-fpm
systemctl enable php-fpm.service【開機自啟動】
/bin/systemctl start php-fpm.service 【啟動php-fpm】

6、查看版本
PHP 5.6.31 (cli) (built: Sep 14 2017 18:12:46) 
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies
with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies

sed -i ‘s/^;date\.timezone\ =/date\.timezone\ =\ "Asia\/Shanghai"/‘ /etc/php.ini

sed -i ‘s/^user\ =\ apache/user\ =\ nginx/‘ /etc/php-fpm.d/www.conf
sed -i ‘s/^group\ =\ apache/group\ =\ nginx/‘ /etc/php-fpm.d/www.conf

/bin/systemctl restart php-fpm.service
/bin/systemctl restart nginx.service

將centos 7 自帶的 php 5.4升級為 5.6