Abstract: Virtual synchronous generator (VSG) not only provides the inertia and damping, but also has the problem of active power oscillation, especially in the system with multiple VSGs. This paper firstly establishes a small-signal model of the active power control link of the VSG parallel system. Then, the influence of damping, inertia and impedance parameters on the system stability is analyzed through the root locus. Furthermore, an improved VSG control strategy based on the transient electromagnetic power compensation is proposed. The first-order lag link is used to construct the transient electromagnetic power to increase the equivalent damping of the system under the transient state and realize the active oscillation suppression of the paralleled operation of the VSGs in the microgrid. This strategy reduces the adjustment time and the impulse power of dynamic processes without causing the steady-state deviations. Finally, the correctness and effectiveness of the proposed strategy are verified by the MATLAB/Simulink simulation and the hardware-in-loop experiment on StarSim.