Combining with the X-ray diffraction technique and the layer-by-layer chemical etch method for peeling damage layers, the depth of the damage layer in InSb crystal introduced by cutting, lapping and polishing was analyzed quantitatively. The structures and causes of damage layers were discussed. The research result showed that cutting was the major process for introducing damage layer on the surface of InSb wafers. The depth of the damage layer introduced by cutting was up to 16 microns. The depth of the damage layer introduced by double-face lapping was about 12 microns. The depth of the damage layer introduced by mechanical-chemical polishing obviously decreased. It was about 2 microns.