According to the irregular shape,size and randomly distributed of diamond grinding abrasive grains,using a random space plane which generates by a random point to segmentation spherical solid based on spherical coordinate,the virtual polyhedron shaped of irregular grains and grinding model is established,which is more close to the actual shape of diamond abrasive grains. In addition,starting from the grinding blade dihedral angle which similar like the cutting tool,using research method with simulating the biology and digital image processing,then a new way of optical density,integral optical density,average integral optical density is presented,the morphology of diamond grinding wheel is evaluated moreover. And through the experimental,the relationship between the grinding blade dihedral angle and integral optical density value are studied. The researched results show that with the dihedral angle increase,the integral optical density increase too in the range from 0 to 200. Finally,combined with the grinding wheel surface area density,the average number of abrasive grain,the protrusion height and the integral optical density value,the effectiveness of the abrasive and grinding wheel model are verified.