A MPPT (Maximum Power Point Tracking) control method of PV (Photovoltaic) generation system is proposed based on the shortcoming of the existing MPPT algorithms. The method applies CVT (Constant Voltage Tracking) algorithm to adjust the working point of PV array near the MPP (Maximum Power Point) for fast tracking when working point is far from MPP, and uses adapting duty cycle perturb method to optimize the steady state characteristic of MPP for effectively eliminate the output power oscillation under the setting precision. Its model is established and simulated with Matlab/Simulink.The CVT, duty cycle method and proposed methods are simulated respectively and simulation results show that, the proposed method tracks the MPP exactly and quickly and improves the energy conversion efficiency of PV generation system by eliminate the output power oscillation around MPP. Its fast response speed improves the static and dynamic performance of photovoltaic power system.