使用以下代码来实现您的需求。

//hook when user registers
add_action( \'user_register\', \'myplugin_registration_save\', 10, 1 );

function myplugin_registration_save( $user_id ) {

    // insert meta that user not logged in first time
    update_user_meta($user_id, \'prefix_first_login\', \'1\');

}

// hook when user logs in
add_action(\'wp_login\', \'your_function\', 10, 2);

function your_function($user_login, $user) {

    $user_id = $user->ID;
    // getting prev. saved meta
    $first_login = get_user_meta($user_id, \'prefix_first_login\', true);
    // if first time login
    if( $first_login == \'1\' ) {
        // update meta after first login
        update_user_meta($user_id, \'prefix_first_login\', \'0\');
        // redirect to given URL
        wp_redirect( \'http://www.example.com/\' );
        exit;
    }
}