The problem of grid-connected inverter reactive power compensation becomes a decisive factor for grid-connected power quality. To ensure the system unit power factor operation, this paper designs a reactive power compensation control strategy for grid-connected inverters based on STATCOM. On the basis of detailed analysis of the working principle of STATCOM, the grid-connected inverter model is built with the help of MATLAB simulation environment. The experimental results show that the use of STATCOM for grid-connected inverter reactive power compensation ensures stable grid-side output voltage of the grid-connected inverter and can improve the power factor of the system at the same time, which has certain reference significance for upgrading the grid-connected inverter design.