The embodiment of the invention provides a method and device for determining data exception, and the method comprises the steps: obtaining a plurality of data packets in a predetermined time period, and enabling the plurality of data packets to have the same data structure; obtaining historical distribution of the historical data with the same data structure; comparing the plurality of data packets with the historical distribution; and determining whether data exception exists or not according to a comparison result. The device corresponds to the method. Through the method and the device, thedata exception in the current data packet can be effectively judged.