1.停止WAMP服务器.
2.下载要安装的PHP版本。下载Window版本的ZIP包啦：http://php.net/downloads.php。解压到 Wamp的安装目录C:wamp64inphpphp7.2.1
3.从已存在的php版本文件中（如phpphp7.1.9 (C:wamp64inphpphp7.1.9）复制以下文件: - php.ini、phpForApache.ini和wampserver.conf到php7.2.1文件夹.
4.打开php7.2.1文件夹的以下文件: - php.ini和phpForApache.ini并且把其中所有的php7.1.9替换为php7.2.1。
5.修改Wamp配置文件：进入 Wamp的安装目录，用IDE或记事本（最好使用行号定位的记事本，如EditPlus等）打开 wampmanager.ini，查询switchPhp7.1.9。
复制：Type: item; Caption: "7.1.9"; Action: multi; Actions:switchPhp7.1.9
插入一行：Type: item; Caption: "7.2.1"; Action: multi; Actions:switchPhp7.2.1
复制：
[switchPhp7.1.9]
Action: service; Service: wampapache64; ServiceAction: stop; Flags: ignoreerrors waituntilterminated
Action: run; FileName: "c:/wamp64/bin/php/php5.6.31/php-win.exe";Parameters: "switchPhpVersion.php 7.1.9";WorkingDir: "c:/wamp64/scripts"; Flags: waituntilterminated
Action: run; FileName: "c:/wamp64/bin/php/php5.6.31/php.exe";Parameters: "switchMysqlPort.php 3306";WorkingDir: "c:/wamp64/scripts"; Flags: waituntilterminated
Action: run; FileName: "c:/wamp64/bin/php/php5.6.31/php-win.exe";Parameters: "refresh.php";WorkingDir: "c:/wamp64/scripts"; Flags: waituntilterminated
Action: run; FileName: "net"; Parameters: "start wampapache64"; ShowCmd: hidden; Flags: waituntilterminated
Action: resetservices
Action: readconfig;
复制插入这行：
[switchPhp7.2.1]
Action: service; Service: wampapache64; ServiceAction: stop; Flags: ignoreerrors waituntilterminated
Action: run; FileName: "c:/wamp64/bin/php/php5.6.31/php-win.exe";Parameters: "switchPhpVersion.php 7.2.1";WorkingDir: "c:/wamp64/scripts"; Flags: waituntilterminated
Action: run; FileName: "c:/wamp64/bin/php/php5.6.31/php.exe";Parameters: "switchMysqlPort.php 3306";WorkingDir: "c:/wamp64/scripts"; Flags: waituntilterminated
Action: run; FileName: "c:/wamp64/bin/php/php5.6.31/php-win.exe";Parameters: "refresh.php";WorkingDir: "c:/wamp64/scripts"; Flags: waituntilterminated
Action: run; FileName: "net"; Parameters: "start wampapache64"; ShowCmd: hidden; Flags: waituntilterminated
Action: resetservices
Action: readconfig;
6. 去C:wamp64inapacheapache2.4.27in删除php.ini文件。
7..重启wamp.
8.选择php7.2.1版本，选择后后会重启wamp。
9.可以打开phpinfo察看此时是否有php7.2.1的信息，然后打开Phpmyadmin,看是否可以访问。
10.完成。