The invention discloses a water-cooling heat-radiating power distribution cabinet which comprises a cabinet body. The cabinet body is composed of a heat-radiating passage positioned on the upper portion, a power distribution chamber positioned on the middle portion and a heat-radiating base positioned on the lower portion, the heat-radiating base comprises an upper-portion partition, an air guidedisc positioned in the middle of the partition and a diversion plate obliquely arranged on the upper portion of the undersurface of the cabinet body, the lower portion of the partition is provided with air incoming fans on two side walls of the cabinet body, and an air guide passage communicating the heat-radiating base with the power distribution chamber is arranged in the middle of the air guidedisc. The air guide disc is driven to rotate through a motor, so that heat-radiating area in the cabinet body can be increased; the air guide disc, the diversion plate, a water collection tank and awater pump form a water cycle through pipelines, so that heat-radiating efficiency of the air guide disc is improved, and the problem of equipment running safety caused by heat generated by electricalelements is eliminated more effectively.