Due to the mixing of single phase load, three phase load and nonlinear load, and the imbalance of load distribution, the unbalanced three-phase voltage of microgrid is more prominent. To solve this problem, an adaptive control strategy based on three phase voltage-imbalance is proposed to adjust the output power of the inverter. First, the block diagram of compensation control for grid connected inverter is established, and a proportional resonant (QR) controller is used to track the current without any static error. Then, the unbalanced state mathematical models of the single low phase voltage and the two low phase voltages are set up. According to the characteristics of the three-phase voltage of the four-bridge arms three-phase inverter with decoupling control, the control of the three-phase voltage is changed to the control of the single-phase voltage. At the same time, the open circuit breakers and the interphase circuit breakers are put forward. The control method is adopted to change the connection state between the phases of the inverter, and the compensation control coefficient is designed. Finally, the simulation results are verified by MATLAB/Simulink. The simulation results show that the compensation control proposed in this paper can effectively compensate the three-phase unbalanced voltage.