以我增加的团购为例：

languages\sc-gbk\admin 中的default.lang.php 文件中底部增加变量值

'groupbuy'=>'团购',
    'groupbuyorder'=>'订单管理',
    'groupbuygoods'=>'商品管理',
    'groupbuyindex'=>'系统配置',

admin\includes 中的menu.inc.php文件中 分别增加

//新增加的团购管理
            'groupbuy_manage' => array(
                'text' => Lang::get('groupbuy_manage'),
                'parent'=> 'groupbuy',
                'url'   => 'index.php?app=groupbuy'
            ),

// 团购
    'groupbuy' => array(
        'text'      => Lang::get('groupbuy'),
        'default'   => 'groupbuyorder',
        'children' => array(
            'groupbuyorder' => array(
                'text' => Lang::get('groupbuyorder'),
                'url'   => 'index.php?app=gbo',
            ),
            'groupbuygoods' => array(
                'text' => Lang::get('groupbuygoods'),
                'url'   => 'index.php?app=module&act=manage',
            ),
            'groupbuyindex' => array(
                'text' => Lang::get('groupbuyindex'),
                'url'   => 'index.php?app=widget',
            ),
        ),
    ),