Abstract: In order to study the effect of metal-bonded diamond grinding wheel cutting edge truncation on the surface morphology of hard and brittle materials, the cutting edge of SD600 metal-bonded diamond grinding wheel was first protruded from the metal bond matrix by means of electric contact discharge (ECD) truing and dressing method, then the different cutting edge heights of diamond grains on the surface of the grinding wheel were truncated by cutting edge truncation way. Finally, the hard and the brittle materials for optical equipment, such as borosilicate glass, quartz glass, quartz crystal and sapphire, were plunge ground with the finished grinding wheel. The results show that the improvement of the roughness of the hard and the brittle materials depends on the types of materials. The maximum roughness R_y of borosilicate glass, quartz glass, quartz crystal and sapphire is reduced by 44%, 34%, 30% and 26% respectively compared with that before grinding wheel ECD truing and dressing, and the quartz crystal material most can be realized ductile grinding.