The issue has been fixed, I enable troubleshooting ,vim bootstrap.php, setup:ini_set('display_errors',1);
ini_set('display_startup_errors',1);
and found error:
Warning: preg_match(): Compilation failed: this version of PCRE is compiled without UTF support at offset 0 in /usr/local/nginx/html/osticket/include/class.validator.php on line 194
Then complie prce and added utf-8 support, then setup the username again.(but cannot use admin).