方案如下： 
修改 includes/lib_insert.php 文件， 
增加一个函数 

/** 
* 调用某商品的累积售出 
*/ 
function insert_goods_sells($arr) 
{ 
$sql = 'SELECT SUM(goods_number) AS number ' . 
' FROM ' . $GLOBALS['ecs']->table('order_goods') ." AS og , " . $GLOBALS['ecs']->table('order_info') ." AS o ". 
" WHERE og.order_id = o.order_id and og.goods_id=".$arr['goods_id']; 
$row = $GLOBALS['db']->GetRow($sql); 
if ($row) 
{ 
$number = intval($row['number']); 
} 
else 
{ 
$number = 0; 
} 
return $number; 
} 

修改模板下goods.dwt文件 
增加一行代码 
<strong>累计售出：</strong>{insert name='goods_sells' goods_id=$id}{$goods.measure_unit}