Silicon carbide ceramics have high hardness, high temperature strength,high thermal conductivity, good chemical stability, small thermal expansion coefficient, good insulation and band gap lamp excellent performance,widely used in aerospace, automotive, machinery, electronics, chemical, energy and environmental protection and other fields.The research shows that:in the preparation process of silicon carbide ceramics, with the reduction of the particle size of silicon carbide powder raw materials, its sintering properties and mechanical properties will be significantly improved, so in order to fire fine ceramic products with excellent performance, it is necessary to have reasonable particle size distribution, high purity and good performance of silicon carbide ultrafine powder.