Conventional evaluation methods are unable to obtain the wear loss of human tooth accurately due to its irregular shape and tiny wear mass loss. A method based on reverse engineering was proposed to evaluate the tooth wear loss. First, a 3D scanning system was used to obtain the point cloud before and after wear test. Second, ICP (Iterative Closest Point) arithmetic in Geomagic studio was used to align the point clouds. Then using 3D comparison and volume calculation, three wear characteristic quantities including largest vertical substance loss, mean vertical substance loss and volume loss were calculated. The results show that this method has the ability to evaluate the wear loss of human tooth effectively and present its shape, which realizes the digitalization, quantification and visualization of the wear loss evaluation of human tooth.