The Maximum Power Point Tracking technology (MPPT) is a basic technology which can improve the efficiency of photovoltaic power generation system. Improving the tracking accuracy and speed and reducing the probability of mis-tracking is the basic research direction in MPPT. In view of the insufficiency in the tracking speed and accuracy of the traditional hysteresis comparison method, this paper proposes an improved hysteresis comparison algorithm, which improve the tracking speed and steady precision of MPPT, additionally, which can avoid the mis-tracking problem with a faster dynamic tracking speed in the case of the environment variation. The results of experiment and Matlab/Simulink simulation proved that the improved method has a faster speed and more accuracy in tracking the maximum power point of PV array, and the improved method can stably work in a dynamic environment%