With the increase of distributed generation (DG), DG is needed to provide inertia for the grid to maintain the security and stability of the grid. Therefore, the virtual synchronous generator (VSG) technology is proposed to compensate for the loss of inertia and reserve capacity. Similar to SGs, the large transient inrush fault current will flow into VSG at the moment of fault, which may lead to the damage of inverters and the instability of the power grid. Therefore, the characteristics of the inrush fault current of the VSG are studied. On the basis of this, a fault current limitation strategy based on adaptive virtual impedance is proposed, and its effectiveness is verified by simulation.