WooCommerce在中提供了更改默认图像的代码this link但根据您的要求，我们必须按如下方式自定义代码

    /*
    * goes in theme functions.php or a custom plugin. Replace the image filename/path with your own :)
    *
    **/
add_action(\'init\', \'custom_fix_thumbnail\');

function custom_fix_thumbnail() {
    add_filter(\'woocommerce_placeholder_img_src\', \'custom_woocommerce_placeholder_img_src\');

    function custom_woocommerce_placeholder_img_src($src) {
        if (is_shop() || is_singular(\'product\') || is_archive() || is_checkout() || is_cart()) {
            global $post;
            $array = get_the_terms($post->ID, \'product_cat\');
            reset($array);
            $first_key = key($array);
            $thumbnail_id = get_woocommerce_term_meta($first_key, \'thumbnail_id\', true);

            // get the image URL for parent category
            $image = wp_get_attachment_url($thumbnail_id);

            // print the IMG HTML for parent category
            if ($image)
                $src = $image;
        }
        return $src;
    }

}

自定义if条件，即根据需要添加和删除条件参数。