默認的版本太低了，手動安裝有一些麻煩，想采用Yum安裝的可以使用下面的方案：

1.檢查當前安裝的PHP包

yum list installed | grep php

如果有安裝的PHP包，先刪除他們

 yum remove php.x86_64 php-cli.x86_64 php-common.x86_64 php-gd.x86_64 php-ldap.x86_64 php-mbstring.x86_64 php-mcrypt.x86_64 php-mysql.x86_64 php-pdo.x86_64

2.Centos 5.X

 rpm -Uvh http://mirror.webtatic.com/yum/el5/latest.rpm
 

CentOs 6.x

  rpm -Uvh http://mirror.webtatic.com/yum/el6/latest.rpm

CentOs 7.X

rpm -Uvh https://mirror.webtatic.com/yum/el7/epel-release.rpm
rpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm

如果想刪除上面安裝的包，重新安裝
rpm -qa | grep webstatic
rpm -e 上面搜索到的包即可

3.運行yum install

yum install php55w.x86_64 php55w-cli.x86_64 php55w-common.x86_64 php55w-gd.x86_64 php55w-ldap.x86_64 php55w-mbstring.x86_64 php55w-mcrypt.x86_64 php55w-mysql.x86_64 php55w-pdo.x86_64

yum install php56w.x86_64 php56w-cli.x86_64 php56w-common.x86_64 php56w-gd.x86_64 php56w-ldap.x86_64 php56w-mbstring.x86_64 php56w-mcrypt.x86_64 php56w-mysql.x86_64 php56w-pdo.x86_64

註：如果想升級到5.6把上面的55w換成56w就可以了。

yum install php70w.x86_64 php70w-cli.x86_64 php70w-common.x86_64 php70w-gd.x86_64 php70w-ldap.x86_64 php70w-mbstring.x86_64 php70w-mcrypt.x86_64 php70w-mysql.x86_64 php70w-pdo.x86_64
4.安裝PHP FPM

yum install php55w-fpm
yum install php56w-fpm
yum install php70w-fpm

5.安裝PHP Redis

yum install php55w-pecl-redis
yum install php56w-pecl-redis
yum install php70w-pecl-redis

註：如果想升級到5.6把上面的55w換成56w就可以了。

Centos下Yum安裝PHP5.5,5.6,7.0