the system already has a web environment, which is 
 php7.1. How to install php5.3 
 and configure 
 the system already has a web environment, which is 
 php7.1. How to install php5.3 
 and configure 
multiple versions of PHP are recommended to be compiled and installed, and you can customize the specified directory, configuration, etc., to avoid conflicts.
recommend an article. You can leave a message if you have any questions.
 Centos7+Nginx+PHP basic WEB runtime environment manual deployment 
  https://my.oschina.net/u/2366...