To solve the problem of the traditional capacitor current proportional feedback active damping method, of which the control structure is complex and resonance damping region is narrow caused by system time delay, the damping method based on the notch filter is instituted and the system resonance region is expended from (0, fs/6) to (0, fs/2), which eliminates the influence of time delay. At the same time, to impair the influence of the resonance frequency fluctuation on the notch filter, the maximum resonance frequency fluctuation range is accumulated by empirical law of classical control theory about the dipoles. Then, the zero and pole map of the close-loop transfer function is used to analyze the system stability. Finally, a reasonable damping ratio is designed. The effectiveness of the designed notch filter active damping method is verified by Matlab/Simulink simulation and experiment. This work is supported by Natural Science Foundation of Shanghai (No. 16ZR1413000) and Shanghai Engineering Research Center of Green Energy Grid-connected Technology (No. 13DZ2251900).