The invention relates to a water-cooling bearing box end cover with a good sealing effect, and belongs to the technical field of bearing cooling. The water-cooling bearing box end cover comprises an end cover body, the end cover body is provided with sleeving stepped holes, and a plurality of first sealing rings are embedded in the inner wall of the sleeving stepped hole with the smallest diameter; a second sealing ring is further embedded in one end, far away from a bearing box, of the end cover body, and the second sealing ring is detachably pressed against the end cover body through a pressing cover; an annular water channel is further arranged in the end cover body, and a plurality of water through holes communicating with the annular water channel are further formed in the end, close to the bearing box, of the end cover body. and a sealing gasket is arranged at the end, close to the bearing box, of the end cover body, the sealing gasket is attached to the end cover body, a plurality of butt-joint flanges are integrally arranged on the sealing gasket, and the butt-joint flanges surround the sleeving stepped holes, the water through holes and connecting screw holes used for connection in the end cover body in a one-to-one correspondence mode. The water-cooling bearing box end cover with the good sealing effect is simple in structure, convenient to assemble and disassemble, good in cooling effect and high in oil leakage prevention capacity.