Submicron grade silicon carbide powder has high purity, low aluminum, low iron, high specific surface area and high surface activity, ensuring the formation of a high density ceramic structure during the pressureless sintering process, improving hardness, wear resistance and thermal conductivity. Its low impurity characteristics reduce sintering defects and are suitable for the manufacture of high-performance ceramic products in high-temperature processes, such as lithium battery sintering and powder metallurgy, to improve production efficiency and product quality.