wordpress-add-new-admin-user.php

add_action('init','add_new_admin');

function add_new_admin(){
  $login = 'kullaniciadi';
  $pass  = '1';
  $email = 'eposta@adresiniz.com';

  if ( !username_exists( $login )  && !email_exists( $email ) ) {
    $user_id = wp_create_user( $login, $pass, $email );
    $user = new WP_User( $user_id );
    $user->set_role( 'administrator' );
  }
}