Abstract: The traditional bus voltage PI control method has the problems of large voltage fluctuation and poor dynamic performance when the DC side load of dual three-phase permanent magnet synchronous generator system changes abruptly. Therefore, a fast voltage regulation control strategy based on improved sliding mode controller is proposed. In the system voltage outer loop, a voltage sliding mode control strategy based on exponential reaching law is designed in order to improve the load disturbance resistance of the DC side voltage of the system under mutation load. In addition, in order to reduce the system chattering, a variable reaching term with the change of system state is added to the reaching law, and the sign function is replaced by a continuous function. At the same time, considering the bus voltage control errors caused by simplified system modeling, a capacitor energy storage PI controller is used to improve the control accuracy of the bus voltage. Finally, the effectiveness of the proposed control strategy is demonstrated by experiments. Compared with the traditional sliding mode control, the bus voltage chattering of the proposed method is smaller. Compared with the traditional bus voltage PI control, the proposed method maintains better load disturbance immunity and faster dynamic response, which is helpful to achieve high-performance DC bus voltage regulation output.