Paste this code in your theme’s functions.php file
add_action('after_setup_theme', 'remove_admin_bar');function remove_admin_bar() {if (!current_user_can('administrator') && !is_admin()) { show_admin_bar(false);}}
If you want to disable it for all users, then simply put use this code in your theme’s functions.php file
show_admin_bar(false);