Abstract: A large amount of renewable energy has changed the damping characteristics of the power system through the access of power electronic equipment, resulting in the prominent problem of low-frequency oscillation of synchronous generators, posing a threat to the safe and stable operation of the system. Virtual synchronous generator (VSG) is a new type of converter control technology, and it is necessary to analyze the damping characteristics of renewable energy integrated to power system based on VSG. Firstly, the mathematical model of the VSG controller and the model of synchronous generator are established. Secondly, taking the renewable energy into the single-machine infinite bus system as the research object, the coupling mechanism of the operation characteristics of the VSG and the synchronous generator is analyzed based on the small-signal analysis. Furthermore, an auxiliary damping control strategy for renewable energy grid-connection is proposed, and a virtual synchronous generator auxiliary damping controller is designed to suppress the low-frequency oscillation of the system based on the principle of pole assignment of the power system. Finally, the simulation results verify the correctness of the theoretical analysis.