adduser user_www
passwd user_www

vi /etc/ssh/sshd_config

// commented:
#Subsystem      sftp    /usr/libexec/openssh/sftp-server

// add:
Subsystem sftp internal-sftp
Match User user_www
ChrootDirectory /usr/share/nginx/html

groupadd group_www

usermod -g group_www user_www

chown user_www:group_www -R /usr/share/nginx/html

service sshd restart

vi /etc/php-fpm.d/www.conf
user = nginx
group = nginx

vi /etc/nginx/nginx.conf
user nginx;

service php-fpm restart
service nginx restart