在 XPath 中索引从 1 个位置开始，因此

In XPath index starts from 1 position, therefore

//div[@class="post-content"]//img[2]

如果您必须在 div[@class="post-content"] 中选择每个第二个 img，

应该可以正常工作.如果您必须从 div[@class="post-content"] 中的所有图像中仅选择第二个 img，请使用:

should work correctly if you have to select each 2nd img in div[@class="post-content"]. If you have to select only 2nd img from all images that are in div[@class="post-content"], use:

(//div[@class="post-content"]//img)[2]