[Abstract] Aiming at the power oscillation caused by the grid connection of large-scale photovoltaic power stations, a control strategy of photovoltaic power stations cooperating with SVG to improve the damping characteristics of the system is proposed based on the control theory. Firstly, the mechanism of additional control of photovoltaic power station equipped with SVG to improve the damping torque of grid connected system is deduced and analyzed. Then the loop forming weight function is optimized by using multi-objective genetic algorithm. The oscillation mode and open-loop model of the system are identified by classical TLS-ESPRIT. The additional robust stabilizing damping controllers of photovoltaic and SVG are designed and the control parameters are adjusted by using the control theory. Finally, a photovoltaic four machine two area grid connection model configured with SVG is built in DIgSILENT. The simulation results show that the damping controller based on control theory attached to photovoltaic and SVG has a good inhibitory effect on the system power oscillation, and the system damping characteristics are continuously improved in the collaborative control mode, which effectively ensures the stability of photovoltaic grid connected system.