In order to solve the adverse effects on the power system when large-scale electric vehicle charging piles are integrated into the power grid, the virtual synchronous generator technology （VSG）is applied to the charging field of electric vehicles. The adjustable inertia and damping are used to enhance the performance of the vehicle-network interconnection system stability. The analysis of the stability of VSG in the charging field based on the method of sequence impedance modeling is the focus. The modeling and control analysis of the virtual synchronous genertater are carried out, and its frequency coupling benefits and coupling characteristics are obtained. The relationship between the control parameters and the stability is analyzed through the derived impedance model. Finally, the simulation waveforms of Matlab/Simulink also verify the analysis results.