The invention relates to a method for detecting power information network traffic abnormality and belongs to the technical field of a power system. The method comprises the steps of data acquisition, standardization treatment, abnormality detection, and abnormality output. In the method for detecting power information network traffic abnormality, a concept of m distances and m neighbors is proposed on the basis of k distances and k neighbors in a LOF (lowest operating frequency) algorithm; abnormal points are detected based on m distances and m neighbors, sensibility of k values in a traditional LOF algorithm is reduced, more attention to data locality is paid and detection accuracy is improved; by the method, power information network traffic can be monitored in real time and network abnormality can be found timely.