The rotor of brushless double-fed pulse generator adopts brushless structure, and the excitation winding and power winding are located in the stator side, with high reliability and flexible excitation mode, so it can be used in pulse capacitor charging system. To solve the static error caused by voltage overshoot and continuous increase when using a PI controller to track the phase voltage of a given power winding in a brushless doubly fed motor capacitor charging system, a fuzzy PI controller is proposed to improve the control strategy of the charging system. First of all, the mathematical model of the brushless doubly-fed motor is established, and the control strategy of variable speed and constant voltage power generation of power winding Flux-Orientation Method is constructed, which solves the problem that the phase voltage of the power side winding constantly decreases with the charging times, and realizes the preliminary tracking of the phase voltage. Then, a fuzzy PI control strategy is proposed to solve the problems of voltage overshoot and static error in PI control system. Finally, the effectiveness of the proposed strategy is verified by model building.