The gear teeth were shocked by high intensity laser shock waves. The transmission error of sample after shocking were tested. The residual stress and microstructure phase transformation were measured by X-ray diffraction (XRD) technique, and the fatigue damage experiment was done to test the fatigue resistant property. The results indicated the tooth profile error after laser processing still kept lower levels and the laser shock had no effecting on transmission accuracy. That the residual compressive stress of gear enhanced greatly after laser processing, and the residual stress of gear was increased by 107% in the normal direction and 85% in the tangent direction. And that the volume fraction of austenite phase decreased after shocked process. The area of defect spot on teeth flank un-shocked was 2.1 times of that shocked, which indicates that the laser shock processing can extend the gear fatigue life.