Abstract: An in-situ transformed carbon fiber toughened alumina ceramic matrix composite was prepared by vacuum hot pressure sintering technology, and the slurry erosion wear behaviour of the composite was tested at different impact angles and velocities on a modified MSH tester. The wear mechanism of the composite and the toughening effect of carbon fiber in the wear process were also analyzed by observing its erosion surface morphology. The results show that C_f/Al₂O exhibits a better wear resistance under the conditions of a larger impact angle and a higher impact velocity. The slurry erosion wear mechanism of C_f/Al₂O₃ is brittle spalling when the surface is repeatedly impacted. The effect of carbon fiber on the erosive wear is bridging the matrix and absorbing the impact energy after cracking. It can inhibit cracks from extending and reduce the loss of the composite.