When large-scale electric vehicles and large-capacity new energy are connected to a power grid, the grid burden and the voltage fluctuate frequently. A Virtual Synchronous (VS) control strategy can be applied to V2G systems. First, a V2G system structure is designed based on the virtual synchronization principle; secondly, the simulation parameters of virtual inertia, damping and excitation characteristics in the VS controller are designed to make the V2G system have the same external characteristics as the traditional grid, and working modes are classified. An experimental environment is built in Matlab R2019a/Simulink to simulate the frequency and voltage disturbance of a power grid while charging and discharging. The typical working mode is simulated and analyzed. Results show the virtual synchronous control strategy has good tracking performance. It can quickly respond to the abnormal power grid, and adjust the active power or feedback the reactive power to the grid in a timely fashion, so as to improve the stability and anti-interference ability. Finally, a V2G prototype with 60 kW power is developed using VS strategy, and the application is completed in the demonstration project site. This work is supported by the National Key Research and Development Program of China (No. 2018YFB0106305).