Abstract: To study the mechanism of SiC fiber (SiC_f) reinforced SiC ceramic matrix composite (SiC_f/SiC) grinding damage, a test platform was built to carry out single abrasive particle scratch tests. The scratch force was measured and the surface damage form was observed. The influence of shape of the abrasive particle, scratch depth and SiC_f orientation on the grinding mechanism was studied. The test results show that the scratch damage of SiC_f/SiC mainly includes matrix collapse, extension, cracks, fractures and pullouts of fiber. In the process of scratching SiC_f/SiC composite material, the scratching force of sharp abrasive particles is smaller, and the surface damage range of the entire scratch caused by sharp abrasive is smaller than that of the scratch caused by flat abrasive particles. However, when the flat abrasive particles are scratching and the fiber orientation is γ=0°, there are fewer damages such as fiber fracture and fiber pull-out in the scratched morphology.