Abstract: To address the issue of off-grid and grid-connected distributed energy and other issues,a control strategy of synchronous inverter is proposed,which enables the grid-connected inverter to provide voltage and frequency support for the power grid. Based on the mathematical model of synchronous generator,and the droop characteristics of active power-frequency and reactive power-voltage,the synchronous inverter is modeled,and the simulation model of single synchronous inverter and droop control is built by MATLAB simulation software. The results show that the control strategy not only has the functions of mechanical rotation inertia,primary frequency modulation and primary voltage regulation,but also can support the power of the power system to stabilize the frequency and voltage of the power system,which is much better than the traditional droop control method and verifies the effectiveness of the proposed control strategy.