The three-loop power virtual synchronous generator (VSG) control methods are commonly used in microgrid inverter (MGI) units to share the loads among the parallel MGI units. In order to achieve stable operation of the MGI units under paralleled or grid-connected mode, a droop synchronization controller is designed in this paper. The difference of phase and amplitude between different MGI units is detected and is used to calculate the output frequency and amplitude of the MGI. The control principle is introduced and the synchronization control block diagram is given. The simulation and experimental results verify that the proposed method is effective in achieving paralleled operation of the MGI units.