I have find out the reason ,find "disable_functions" in php.ini
disable_functions = scandir,passthru,exec,system,chroot,chgrp,chown,shell_exec,proc_open,proc_get_status,ini_alter,ini_alter,ini_restore,dl,pfsockopen,openlog,syslog,readlink,symlink,popepassthru,stream_socket_server,fsocket,fsockopen
and delete "scandir"
restart php-fpm
that's it