Method, scanner, device and system for identifying webpage distortion

The invention provides a method, scanner, device and system for identifying webpage distortion. The method comprises the steps of receiving an expected page element set, sent by a website side through a first page response, of a monitored page, receiving a real page element set and a refreshed page element set sent by the website side through a second page response, calculating a reference page element set according to the expected page element set, the real page element set and the refreshed page element set, and judging whether the monitored page is distorted or not according to the reference page element set, the real page element set and the expected page element set. According to the method, the aim of judging whether the monitored page is distorted or not on the side of the canner is achieved, that is, in the view of a client side, webpage distortion is identified, and the situation that in the prior art, a method for identifying the webpage distortion cannot accurately judge whether the webpage is distorted or not is avoided.