TiN, TiCN, TiAlN and Al2O3 are coated on the cemented carbide tool with one or more layers of wear resistance, and the thickness of the coating is 2 to 18mm. The role of coating can reduce friction and reduce the formation of cutting heat; low thermal conductivity, can weaken the thermal effect on the tool. Coated carbide cutting tools and carbide tools, both in strength, hardness and wear resistance have been greatly improved, for example: the hardness of HRC45 ~ 55 in the workpiece, the coating carbide tool High-speed turning.