Wind shear and tower shadow effect make direct drive wind power become forced power oscillation disturbance sources, and virtual inertia control makes wind power have the capacities of both the inertia support for the grid and the disturbance suppression. This paper presents an improved virtual inertia control though analyzing the system damping, the torsional vibration and the disturbance source affected by the proportional differentiation coefficients. The proportional differentiation coefficients are enlarged equivalently and simultaneously through adding the reference value of the wind power output and a two-order band pass filter in compensation value of virtual inertia control. The results of analysis and simulation in the example show that the disturbance suppression capacity of virtual inertia control is enhanced on the premise of not decreasing the system damping and the torsional stability. This work is supported by National Natural Science Foundation of China (No. U1510112).