Virtual synchronous generator (VSG) can make the inverter have the dynamic response capability similar to that of traditional synchronous machine, which is a common Grid-Forming control technology. If VSG’s virtual inertia, damping coefficient and other parameters are not dynamically adjusted according to the power grid strength, the dynamic response may be too slow or too fast, bringing potential stability problems. Therefore, this paper is developed on the basis of the existing virtual impedance control, a virtual impedance control method considering dynamic process is proposed in this paper. The variable parameters of virtual impedance are adjusted by constructing high-order polynomials to provide suitable damping torque for the system. Furthermore, the stability characteristics of the VSG grid-connected system under dynamic virtual impedance regulation are modeled and evaluated based on the sequential impedance theory, which provides a theoretical basis for optimizing design parameters and improving system stability. Simulation results verify the effectiveness of the proposed dynamic virtual impedance control.