Aiming at the unsatisfactory effect of MPP tracking when the light intensity changes rapidly, a novel and improved incremental conductance method is proposed based on the study of PV battery output characteristics and incremental conductance method of photovoltaic power generation system. The paper firstly introduces the photovoltaic power generation system; secondly, it analyzes and studies the traditional incremental conductance method and summarizes its shortcomings; then, according to the shortcomings of the traditional incremental conductance method, a novel and improved method is proposed. Incremental conductance method, divided and analyzed the four sections of the I-U characteristic curve and designed the variable-step incremental conductance method; finally, built the simulation of the traditional incremental conductance method and the improved incremental conductance method in the Matlab/Simulink environment The two algorithms are compared and simulated under the condition of rapid change of light intensity. The simulation results show that when the light intensity changes rapidly, the novel improved incremental conductance method not only has the advantages of no oscillation in steady state and fast response speed, but also can make the system output more power and improve the efficiency of photovoltaic power generation , which better realizes the fast and accurate tracking of MPP.