By simulating the characteristics of the traditional synchronous generator, virtual synchronous machine technology allows the power supply using the converter to have the characteristics of inertia, damping, frequency and voltage adjustment of the synchronous generator. It is an important technical means for the stable operation of the new energy power generation connected to the power grid. This paper proposes an electromechanical transient modeling method of energy storage based on virtual synchronous machine technology. The energy storage model includes virtual synchronous machine control, energy storage restriction and a model interface module, and takes into account the rotor equation of the virtual synchronous machine, energy storage charge and discharge power, charged state, operating efficiency, dead zone and inverter limitation characteristics. Based on power system analysis and a synthesis program, the model is built by a user-defined method. The IEEE 4 machine 2 region and Henan power grid are selected for simulation verification. The simulation results show that the modeling technology proposed has advantages over the traditional method. This work is supported by the National Natural Science Foundation of China (No. 51607158).