The invention discloses a ceramic nut cap which is acquired by cutting a ceramic nut cap array. The ceramic nut cap array comprises a ceramic wafer and a ceramic cover plate connected by adhesion, theceramic wafer is cuboid, and a plurality of through holes are formed in the side surface, far away from the ceramic cover plate, of the ceramic wafer. The ceramic nut cap and the preparation method thereof provided by the invention are processed on the ceramic cover plate and the ceramic wafer, so that preparation of a ceramic nut cap blank with small size is not needed, and high-temperature sintering of the ceramic nut cap blank is not needed either, and thus the ceramic nut cap is prevented from being shrunk and deformed due to high-temperature sintering, good in packaging effect, capable of meeting the requirement of small size and reduced in material waste.