Abstract: The traditional virtual synchronous generator (VSG) control scheme and the existing VSG-based state of charge (SOC) balancing scheme of the microgrid lithium battery inverter cannot achieve SOC balancing of non-equal capacity lithium batteries. In order to achieve SOC balancing of non-equal capacity lithium batteries, a non-equal capacity lithium battery SOC balancing scheme based on VSG control is proposed. By modifying the traditional VSG control parameters and line impedance parameters, the inverter output active power is proportional to the battery capacity, eliminating the influence of capacity on SOC, and then the inverter output active power with SOC is adjusted as the variable to achieve SOC balancing for non-equal capacity lithium batteries. In addition, a VSG small signal model is established to analyze the influence of control parameters on system stability. Finally, the Matlab/Simulink simulation software and experimental platform are used for simulation and experimental verification. The results show that the proposed scheme can be adopted to achieve SOC balancing of multiple equal and non-equal capacity lithium batteries, extend the service life of lithium batteries. It is verified that the control parameters can affect the system stability.