需要改动的两个文件：

template\checkout\cart.phtml,,,把如下代码加到适当位置

<form action="<?php echo $this->getUrl('checkout/cart/deleteCart') ?>" method="post">
<button type="submit" title="<?php echo $this->__('Delete Shopping Cart') ?>"><span><span><?php echo $this->__('Delete Shopping Cart') ?></span></span></button>
</form>

app\code\core\Mage\Checkout\controllers\CartController.php

代码如下：

public function deleteCartAction()
{
$cart = Mage::getSingleton('checkout/cart');
foreach( Mage::getSingleton('checkout/session')->getQuote()->getItemsCollection() as $item ){
$cart->removeItem( $item->getId() );
}
$cart->save();
$this->_goBack();
}

效果如下图所示：

delete shopping cart 按钮即可以清空magento购物车里面，所有的物品。。。。