The invention discloses a method and device for determining a webpage loading speed. The method comprises the following steps: analyzing access data of a target website to obtain access data in which the same source in the same session accesses the same webpage exceeding a preset access time, extracting a dwell time of the same source in the same session in the same webpage from the obtained access data, and determining whether the accessed webpage is a webpage with a low loading speed according to the dwell time. By adoption of the method and device disclosed by the invention, the technical problem that the webpage with the low loading speed cannot be accurately judged is solved.