There are problems of power grid impact and line overload caused by one-way charging of electric vehicles on a large scale. Thus research and application of electric vehicle V2G technology in a multi-energy system are carried out. First, the technical advantages and disadvantages of several typical multi-energy system topologies are compared, and V2G technology is adopted in a multi-energy system based on a common AC bus. Secondly, an autonomous active and reactive power control strategy for V2G based on a virtual synchronous machine is proposed to optimally design key parameters such as virtual inertia, damping, etc., simulate the electromechanical transient characteristics of traditional generator sets, realize the independent voltage and frequency regulation, and solve the problem of grid index fluctuation caused by the intermittent nature and randomness of photovoltaic power generation. Thirdly, a typical multi-energy system is established for simulation, and results show that the V2G equipment based on a virtual synchronous machine can actively track the changes of frequency and voltage at the connection point, and provide active or reactive power support in time. This effectively ensures the stability of power grid operation. Finally, a 500 kW high-power V2G equipment based on the virtual synchronization strategy is developed and successfully applied in the demonstration project, verifying the effectiveness of the proposed method. This work is supported by the National Key Research and Development Program of China (No. 2019YFE0118700).