Due to changes in external environmental factors, Which will cause the power-voltage output characteristic curve changes. In order to improve the MPP tracking speed and mitigate the oscillation problem near the MPP point in the maximum power tracking process of the photovoltaic power generation system,An adaptive MPPT algorithm based on selecting the duty cycle disturbance is proposed. This method selects the appropriate duty cycle disturbance value by judging the derivative value of the power to voltage, which better solves the contradiction between rapidity and stability problem. Finally, the superiority of the new control method is verified by building Matlab/Simulink model.