Abstract: To improve the lapping quality and processing efficiency of single-crystal SiC, solid-state Fenton reaction lapping pellets were prepared. Effects of particle size and concentration of Fe₃O₄ solid-phase catalyst on the physical properties (hardness, flexural strength, porosity), catalytic performance, and lapping performance of single-crystal SiC were studied. The results showed that with the increase of Fe₃O₄ particle size, the hardness, flexural strength, porosity, and catalytic performance of the lapping pellets all decreased, the material removal rate (MRR) decreased from 43.12 nm/min to 36.82 nm/min, and the surface roughness (Ra) increased from 1.06 nm to 3.72 nm. As the Fe₃O₄ concentration increased, the hardness and flexural strength of the lapping pellets decreased, and the porosity and catalytic performance increased. Although the material removal rate decreased, the surface roughness (Ra) decreased firstly and then increased. The MRR decreased from 40.14 nm/min to 33.51 nm/min, the surface roughness (Ra) was 3.25 nm, 1.75 nm and 1.88 nm. In this experiment, when the Fe₃O₄ particle size and the concentration was 0.5 µm and 29 wt.%, the processing effect was the best, the MRR and the surface roughness (Ra) was 43.13 nm/min and 1.06 nm.