Because of laser radar having extremely high detection sensitivity, the micro-Doppler effect is obvious in laser radar detection process. At present, the study of micro-Doppler of rotor blades is almost based on the hovering helicopter, however, helicopters are taking various motion in the actual condition. In this paper, the RCS of a helicopter rotor was calculated, and a micro-Doppler model of a helicopter rotor was established. Based on the model, taking the AH-64 armed helicopter for example, the micro-Doppler effect of the rotor blades in radar detection process was simulated and calculated, of which was taking the uniform linear moving and the face upward moving. The results show that the motion state of the helicopter can be judged primarily through analyzing the range profiles of the distance and the frequency spectrum of the micro-Doppler effect of a helicopter's blades in radar detection process, which provides some reference for moving helicopter identification by micro-Doppler.