Abstract: SiC ceramics were prepared by different SiC particle gradations (the mass ratio of SiC particles diameter of 11.3 μm to 3.8 μm were 0.75∶1, 0.5∶1, 0.4∶1) slip casting and reaction-sintering menthod, and then erosion wear testing was performed with different quartz abrasive particles of 300-600 μm and 600-850 μm at different impact angles. Combining with the worn surface morphology to analyse the effect of particle gradation on erosion wear performance and mechanism. The results show that the SiC ceramic prepared by reaction-sintering slip casting green body with particle gradation of 0.75∶1 had the highest density, and its erosion wear rate was the lowest at the same impact angle. The erosion wear rate of SiC ceramic first increased and then decreased with the increase of impact angle and up to the maximum at impact angle of 60°. The bigger the quartz abrasive particle size, the more the erosion wear rate. The erosion wear mechanism was dominated by spalling of free silicon, free carbon and SiC particles.