非常简单。。。使用自定义Walker。。。您所需要做的就是将某个常量附加到id元素。。。例如实际的帖子或页面id。。。在菜单项->对象id中。。。我真的不明白你为什么这么做。。。通过对CSS的粗略了解，您可以轻松地利用级联来处理子项。。。所有菜单项都已分配了css类@看见the Codex

$args = array (

\'theme_location\'  => \'primary\',
\'menu\'            => \'Menu Name\',
\'container\'       => \'div\',
\'container_class\' => \'nav\',
\'container_id\'    => FALSE,
\'menu_class\'      => FALSE,
\'menu_id\'         => FALSE,
\'echo\'            => TRUE,
\'fallback_cb\'     => \'wp_page_menu\',
\'before\'          => FALSE,
\'after\'           => FALSE,
\'link_before\'     => FALSE,
\'link_after\'      => FALSE,
\'items_wrap\'      => "\\n\\t" . \'<ul>%3$s</ul>\' . "\\n",
\'depth\'           => 0,
\'walker\'          => new ID_Walker()
);

wp_nav_menu( $args );

class ID_Walker extends Walker_Nav_Menu {

function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
    global $wp_query;
    $indent = ( $depth ) ? str_repeat( "\\t", $depth ) : \'\';

    $class_names = $value = \'\';

    $classes = empty( $item->classes ) ? array() : (array) $item->classes;
    $classes[] = \'menu-item-\' . $item->ID;

    $class_names = join( \' \', apply_filters( \'nav_menu_css_class\', array_filter( $classes ), $item, $args ) );
    $class_names = $class_names ? \' class="\' . esc_attr( $class_names ) . \'"\' : \'\';

    $id = apply_filters( \'nav_menu_item_id\', \'menu-item-\'. $item->ID, $item, $args );

            /** 
            * Add the object id as a reference
            * This will tie your menu_item id ref to your post page or cpt
            */  

    $oid = esc_attr( $item->object_id ); 

            /**
            * Append the object id to the element id  
            */

    $id = $id ? \' id="\' . esc_attr( $id ) . \'-\' . $oid . \'"\' : \'\';

    $output .= $indent . \'<li\' . $id . $value . $class_names .\'>\';

    $attributes  = ! empty( $item->attr_title ) ? \' title="\'  . esc_attr( $item->attr_title ) .\'"\' : \'\';
    $attributes .= ! empty( $item->target )     ? \' target="\' . esc_attr( $item->target     ) .\'"\' : \'\';
    $attributes .= ! empty( $item->xfn )        ? \' rel="\'    . esc_attr( $item->xfn        ) .\'"\' : \'\';
    $attributes .= ! empty( $item->url )        ? \' href="\'   . esc_attr( $item->url        ) .\'"\' : \'\';

    $item_output = $args->before;
    $item_output .= \'<a\' . $attributes .\'>\';
    $item_output .= $args->link_before . apply_filters( \'the_title\', $item->title, $item->ID ) . $args->link_after;
    $item_output .= \'</a>\';
    $item_output .= $args->after;

    $output .= apply_filters( \'walker_nav_menu_start_el\', $item_output, $item, $depth, $args );
    }
}

只需将自定义函数添加到nav_menu_item_id hook 这样做：

function custom_nav_menu_item_id($menu_id, $item, $args, $depth) {
    if ($item) {
        switch ($item->object) {
            case "page":
                // If the menu item\'s object is a page,
                // retrieve it and return its name.
                $post = get_post($item->object_id);
                return $post->post_name;

            case "category":
                // If the menu item\'s object is a category,
                // retrieve it and return its slug.
                $category = get_category($item->object_id);
                return $category->slug;
        }
    }

    // Return the standard menu id by default.
    return $menu_id;
}

add_filter(\'nav_menu_item_id\', \'custom_nav_menu_item_id\', 10, 2);