To modify the grinding effect of rails, superhard composite abrasive grains were used to make resin bond test specimens through processes of press-sintering and then curing. The effects of the grain type on the bending strength, the impact strength and the abrasive wear ratio of the specimens were studied and the ground surfaces of the abrasives and rails were observed by using SEM to characterize the quality of ground surface. Results show that after the grain and metal bond are granulated, all three types of mentioned performance of the specimens are significantly improved, i.e. bending strength 50% higher, impact strength nearly 2 times larger and wear ratio about 12.6 times larger. In conclusion, superabrasive, when added as composite grains, could enhance the bonding force of the tool on its grains and reduce the phenomenons such as bluing and burning, thus achieving a better surface quality of the rail.