Abstract: A TiB2 coating carbide milling cutter and a diamond coating carbide milling cutter were used to cut carbon fiber reinforced plastics (CFRPs ) in order to study the wear morphology and wear mechanism of these two carbide tools by scanning electron microscopy and three-dimensional video microscopy. The results show that the alternate stress generated during the alternately cutting of soft resin matrix and high strength carbon fiber and the high frequency impact of the high strength carbon fibers on the tool edge caused the chipping and coating peeling of the tools. The life of diamond coating cutter was significantly higher than that of the TiB2 coating cutter, and the surface roughness of the former was also lower than that of the latter because of high hardness and wear resistance of diamond coating. Abrasive wear was the wear mechanism of these two cutters.