The invention provides an active electric network supporting load virtual synchronous device control method, which comprises the following steps of bringing a system real-time perturbation total quantity into an expansion state observation device of a prebuilt load virtual synchronous device; performing calculation to obtain a system perturbation estimation value; using the system perturbation estimation value as a compensation item of a virtual torque in the active control to compensate the virtual torque. By using the technical scheme provided by the invention, the expansion state observation device is applied to the design of a control strategy; the observation is performed through the expansion state observation device; the observation value is used as the virtual torque for compensation; the perturbation resistance capability of the system is improved, so that the voltage and the power can be continuously and stably output.