In view of the large size, high power consumption, poor heat dissipation, and high noise of marine electrical equipment, the sensor and control unit of the water cooling system of marine electrical equipment was studied, and the typical characteristics of the electrical equipment body, circulating water system, monitoring and protection device were studied. In summary, a water-cooling system for marine electrical equipment based on modular water-cooling panels and sensing and control technology is proposed, and the volume, power consumption, heat dissipation, and noise of the water-cooling system are tested using joint commissioning tests and actual ship electrical equipment. The research results show that the system can improve the power density, stability, cooling efficiency, and noise level of ship electrical equipment, and can ensure the superiority of ship electrical equipment in volume, power consumption, heat dissipation, and noise.