Abstract: In order to compare the advantages and disadvantages of existing different sliding bearing water-cooling systems of main motors in large pump stations, the heat generated and heat transfer performances of the sliding thrust bearing and guide bearing in the motor oil cylinder were calculated, and the relation between the minimum required cooling water flow and inlet water temperature under the bearing temperature control conditions was obtained. Four kinds of water-cooling systems were introduced: the traditional water supply and drainage system, the coil system, the plate heat exchanger system and the chiller system. The operation energy consumptions of the four kinds of water-cooling systems were calculated and analyzed, and a comprehensive comparison analysis was also made. The results show that the traditional water supply and drainage cooling system has high energy consumption, the pump suction inlet pipe is easy to block, and the inner wall of oil coolers is easy to scale. Compared with the traditional water supply and drainage cooling system, the coil water cooling system saves 22.9% energy and has no problems of blockage and scaling. The plate heat exchanger cooling system saves energy by 45.5% with the highest energy-saving rate, but there are still problems of blockage and scaling. The chiller cooling system takes the second place with an energy-saving rate of 39.6%, howe-ver, it has the comprehensive advantages of energy saving, no scaling, no water inlet blocking and convenient operation and maintenance.