A simplified impact model including a damping term is used to predict the transient contact force, and the dynamic response of blade droop stop impact is studied. The Hamilton principle is used to derive the dynamics equations during blade droop stop, and the Newmark integration method is used to solve the equations. The influences of hinge spring stiffness, damping ratio and integration step on the contact moment are analyzed. The results show that the peak impact moment increase by 22.0 times, when the spring stiffness is increased by 1000 times. The peak impact moment is increased by 10.4%, when the damping ratio changes from 0 to 0.05. The accuracy of calculation increases with smaller time integral step, but the efficiency decreases.