For the misjudgment and oscillation in the traditional MPP tracking process when the light intensity changes rapidly, a novel improved optimal gradient method for power prediction is proposed, based on the research of the traditional power prediction method and the optimal gradient method.In this article, the working principle, advantages and disadvantages of the traditional power prediction method and optimal gradient method are firstly analyzed; then a novel power prediction method with high-precision power calculation, as we as an improved optimal gradient method are proposed. Finally, Simulink simulation analysis is carried out on the proposed MPP tracking strategy when the light intensity changes rapidly. The simulation results show that when the light intensity changes rapidly, the novel power prediction improvement is adopted. The optimal gradient method can not only eliminate the misjudgment phenomenon and oscillation phenomenon, but also the power calculation is more accurate. The introduction of the variable step factor can make the system output more power, which can well realize the fast tracking of MPP.