The sintering process is the most critical link in the preparation of boron carbide. Boron carbide sintering is difficult because the bonding bond of boron carbide is strong covalent bond, and the shape is poor, the grain boundary moving power is large, and the surface tension in solid state is very small. In recent years, with the development of the preparation of ultrafine powder technology and the development of effective sintering additives, make the conventional sintering of boron carbide problem is resolved, thus has a wide application, the method of preparing boron carbide powder at home and abroad: carbon tube furnace or electric arc furnace carbon thermal reduction process, magnesium hot method, laser induced by CVD method, direct making method, sol gel carbon thermal reduction process, etc.