1、新建用户iicms
2、修改/etc/ssh/sshd_config,最下面
Subsystem sftp internal-sftp
Match User iicms  ## 用户
        ChrootDirectory /usr/local/nginx/html/images  ## ftp存放路径
        X11Forwarding no
        AllowTcpForwarding no
        #PermitTTY no
        ForceCommand internal-sftp

3、重启sshd