PhotovoltaicSPower system is easily influenced by unstabilizing factors, which can cause the misjudgment of maximum power point tracking. According to the effect of the changing load on the Maximum Power Point Tracking of PhotovoltaicSPower, a new maximum power point tracking method is presented to prevent the misjudgment of maximum power point tracking. The method can test and calculate maximum power point correction which is superposed to the power of maximum power point, and compensate for power in the process of the maximum power point tracking, which can avoid the phenomenon of misconception. The experiment results show that, the improved method can avoid the misjudgment and obtain betterStracking under the changing load. Compared with traditional perturbation and observation, the new control method of maximum power point tracking improve the efficiency of Grid-connected PV.