Load monitoring is of great significance to the power system. Traditional load monitoring requires the installation of sensors and other hardware devices at each monitored load. This intrusive load monitoring method requires a lot of manpower, material and financial resources. For this reason, a non-intrusive load monitoring method is proposed, in which the load operation can be analyzed by installing the monitoring equipment at the power inlet and monitoring the current and voltage signals. Therefore, noninvasive power load monitoring is one of the important development directions of power load monitoring in the future. Different power loads typically exhibit different characteristics in switching and cutting. Accordingly, we propose an automatic detection algorithm for transient events based on difference of current intensity, it can according to the identification of the load current signal accurately switching occurs at the moment and moment load shedding occurred and trigger the relevant program to these time points recorded, and then the application of the procedure for further processing