The application of large-capacity battery energy storage can stabilize the fluctuation of the distributed generations’ output power and improve the operation stability of power grid. According to the inertia and damping characteristics of traditional synchronous generator, this paper propose that "virtual synchronous generator" control technology can be used to control the converter of battery energy storage system, to realize the voltage regulation and power control of the system. In this paper, the control strategy of the energy storage system is designed, to stabilize the output power of the integrated distributed generation, and to realize the voltage and frequency control of system during grid-connected operation, islanded operation and the state switching between these two operation modes. Finally, the Simulink/Matlab simulation proves that the control strategy is feasible and effective.