Hot pressure sintered boron carbide ceramic sealing ring has such advantages as high compact density, high hardness, strong corrosion resistance, excellent wearing quality, small friction coefficient, oxidation resistance, small creeping bentgrass at high temperature, good thermal stability, so it is widely applicable to feeding pump with liquid contained large numbers of solid granule and liquid with strong causticity. Particularly it is suitable for using in such cases to be required with no any leakage as working condition of feeding strong acid, strong alkali and causticity liquid.