With the increasing integration of renewable energy sources into power grids, the demand for energy storage systems with fast response and grid-support capabilities has grown significantly. Against this background, this paper investigates the grid-forming flywheel energy storage system, which is capable of providing inertia and frequency regulation to enhance grid stability. An integrated control strategy is proposed, combining voltage-type PWM dual-loop control on the motor side with virtual synchronous generator (VSG) technology on the grid side. Through MATLAB/Simulink simulation, the results demonstrate that the proposed strategy can rapidly stabilize the system, exhibiting superior dynamic performance and robustness. Furthermore, it performs well in complex scenarios such as load mutations and frequency fluctuations, making it a promising solution for modern power systems.