Abstract: As a critical guarantee for the safe and stable operation of converter stations, the water cooling system exhibits prominent operational noise issues caused by its internal high-power asynchronous motors and centrifugal pumps, which not only severely affect the physical and mental health of operation and maintenance personnel but also induce the NIMBY effect of converter stations. This paper proposes a solution to replace traditional main circulation pumps with high-power canned motor pumps to achieve effective noise reduction. Based on measured data from an engineering project, the operational noise of a conventional 200 kW main circulation pump at a distance of 1 m ranges from 92 to 95 dB, whereas that of a 190 kW canned motor pump at the same distance can be reduced to 76–79 dB. Furthermore, leveraging the unique structure of the canned motor pump, an optimized design incorporating a filter at the inlet of the main circulation pump in the internal cooling water system is proposed. The research demonstrates that the high-power canned motor pump not only features low-noise operation but also enables maintenance-free performance of the main circulation pump, thereby safeguarding the health of operation and maintenance personnel while enhancing operational efficiency.