1，在CentOS7安装epel源,(原服务器上要有php环境以及php的进程管理器php-fpm)
yum -y install epel-release

2，安装phpMyAdmin软件
yum -y install phpmyadmin

3，为了使Nginx Web服务器正确地查找和提供phpMyAdmin文件，我们只需要创建一个从安装文件到我们的Nginx文档根目录的符号链接：
ln -s /usr/share/phpMyAdmin /usr/share/nginx/html

4，配置nginx，如下图

5，重新启动我们的PHP处理器，以确保它可以加载我们安装的额外的PHP模块：
systemctl restart php-fpm

6，这样，我们的phpMyAdmin安装现在可以运行。 要访问该界面中，转至服务器的域名或公网IP地址，后跟/phpMyAdmin ，在网页浏览器
http://server_domain_or_IP/phpMyAdmin

7，我们可以授权我们的mysql数据库服务器对外远程访问
登录mysql数据库
msyql -uyourusername -pyoupassword
mysql > grant all privileges on . to yourMysqlUser@'%' identified by 'your password';
mysql > flush privileges;
mysql > exit;

8，测试并验证

9，若是有多个需要连接的数据库，可以修改phpMyAdmin的配置文件，修改根目录/etc/phpMyAdmin中的config.inc.php配置
$i = 0;

/*

• 服务器A
  /
  $i++;
  / Authentication type */
  $cfg['Servers'][$i]['auth_type'] = 'config';
  $cfg['Servers'][$i]['host'] = '127.0.0.1';
  $cfg['Servers'][$i]['port'] = '3307';
  $cfg['Servers'][$i]['connect_type'] = 'tcp';
  $cfg['Servers'][$i]['compress'] = false;
  $cfg['Servers'][$i]['extension'] = 'mysqli';
  $cfg['Servers'][$i]['user'] = 'root';
  $cfg['Servers'][$i]['password'] = '123456';
  $cfg['Servers'][$i]['bs_garbage_threshold'] = 50;
  $cfg['Servers'][$i]['bs_repository_threshold'] = '32M';
  $cfg['Servers'][$i]['bs_temp_blob_timeout'] = 600;
  $cfg['Servers'][$i]['bs_temp_log_threshold'] = '32M';

/*

• 服务器B
  */
  $i++;
  $cfg['Servers'][$i]['auth_type'] = 'config';
  $cfg['Servers'][$i]['host'] = '127.0.0.1';
  $cfg['Servers'][$i]['port'] = '3308';
  $cfg['Servers'][$i]['connect_type'] = 'tcp';
  $cfg['Servers'][$i]['compress'] = false;
  $cfg['Servers'][$i]['extension'] = 'mysqli';
  $cfg['Servers'][$i]['user'] = 'root';
  $cfg['Servers'][$i]['password'] = ‘123456';
  $cfg['Servers'][$i]['bs_garbage_threshold'] = 50;
  $cfg['Servers'][$i]['bs_repository_threshold'] = '32M';
  $cfg['Servers'][$i]['bs_temp_blob_timeout'] = 600;
  $cfg['Servers'][$i]['bs_temp_log_threshold'] = '32M';

/*

• 服务器C
  */
  $i++;
  $cfg['Servers'][$i]['auth_type'] = 'config';
  $cfg['Servers'][$i]['host'] = '127.0.0.1';
  $cfg['Servers'][$i]['port'] = '3306';
  $cfg['Servers'][$i]['connect_type'] = 'tcp';
  $cfg['Servers'][$i]['compress'] = false;
  $cfg['Servers'][$i]['extension'] = 'mysqli';
  $cfg['Servers'][$i]['user'] = 'root';
  $cfg['Servers'][$i]['password'] = '123456';
  $cfg['Servers'][$i]['bs_garbage_threshold'] = 50;
  $cfg['Servers'][$i]['bs_repository_threshold'] = '32M';
  $cfg['Servers'][$i]['bs_temp_blob_timeout'] = 600;
  $cfg['Servers'][$i]['bs_temp_log_threshold'] = '32M';
  保存，打开phpmyadmin,在首页就可以看到服务器列表了

10，可参考内容如下
https://www.howtoing.com/how-to-install-and-secure-phpmyadmin-with-nginx-on-a-centos-7-server