The traditional microgrid electric energy system exhibits low damping and low inertia, making it susceptible to load fluctuations that can significantly impact the system. A new study suggests a way to control a microgrid virtual synchronous generator (VSG) using adaptive regulation of rotational inertia. This lowers the frequency steady-state offset of the VSG control system’s output by using a non-differential frequency regulation method. The virtual excitation regulator regulates the output voltage deviation. Meanwhile, we establish a small-signal model of the grid-connected inverter based on VSG control and explore the effects of rotational inertia and damping coefficient on the stability of the VSG. The MATLAB/Simulink simulation tool is used to simulate the microgrid differential power load mutation, and the effects of the VSG control and the traditional control strategy on several aspects of the system, such as frequency regulation, power regulation, and power quality, are analyzed by comparison. The findings show that the suggested adaptive control method lowers the voltage amplitude from ±25V to ±10V when the system is isolated, stops power fluctuations, and makes the output response curve as good as it can be. Under grid-connected conditions, the VSG adaptive control method still ensures better control performance, but it does not show a significant advantage in this experimental condition.