修改核心文件：app/code/core/Mage/Catalog/Model/Product.php

#注：当然你也可以重写个local

找到Delete()方法然后最前面增加一下代码即可。

foreach ($this->getMediaGallery('images') as $image) {
            $image_path = $this->getMediaConfig()->getMediaPath($image['file']);
            if (file_exists($image_path)) {
                @unlink($image_path);
            }
        }