Abstract: When the photovoltaic module is partially shaded, the problems of false tracking, slow tracking speed and low output power usually appear in the process of maximum power point tracking（MPPT）. To make the maximum power output process of photovoltaic modules fast, stable and accurate under partial shading condition, a composite MPPT algorithm（INC-GCA） was proposed based on incremental conductivity algorithm（INC） and global comparison algorithm（GCA）. To verify the algorithm, a Simulink simulation model was built, and a photovoltaic experimental platform was designed. The results show that when the photovoltaic module is partially shaded, the composite algorithm based on INC algorithm and GCA can accurately track the maximum power with fast tracking speed and high reliability, and the problem of false tracking is completely avoided. Compared with the incremental conductance method, the proposed algorithm can effectively improve the power generation efficiency of the photovoltaic system and improve the economic benefits of the photovoltaic power station.