Abstract: A new normalized first-order spatial amplitude spectrum three-dimension(3-D) recognition method based on grating modulation was presented to speed up and improve ability for 3-D recognition.The theoretical model was established in detail,the properties of rotation and shift were theoretically and practically analyzed to conclude its shift invariant speciality.Experiments showed its flexibility.It can not only recognize 3-D object efficaciously,but also estimate the rotated angle of the 3-D object with higher resolution of ±2°.Because only one frame of sinusoidal grating needs to be projected and only one frame of the deformed fringe pattern needs to be collected in this method,it may be very suitable to be applied in dynamic or on-line 3-D recognition.