When the grid voltage is asymmetrical, the current at the point of common coupling (PCC) will contain negative sequence components, and the reactive power and active power of the grid will oscillate at 100Hz, seriously polluting the power quality of the grid. This paper develops a negative-sequence VSG-based positive-negative sequence separation control strategy. With reference to the circuit equivalent model under asymmetrical grid voltage, analyzing the VSG model and the current and power characteristics under asymmetrical grid voltage. Designing negative sequence VSG control and adding it to the traditional VSG control. The suggested control strategy is tested in MATLAB/Simulink, and the findings demonstrate that while reducing power oscillations, it also removes the negative sequence currents of VSG under unbalanced grid voltage.