The invention discloses a vacuum centralized water diversion system for a ship. The vacuum centralized water diversion system for the ship comprises an automatic control device, a sliding-vane rotary vacuum pump, a first motor connected with one end of the sliding-vane rotary vacuum pump, a vacuum box connected with the other end of the sliding-vane rotary vacuum pump and a liquid level detection device connected with the vacuum box; the liquid level detection device is connected with a plurality of centrifugal pump water diversion assemblies, and a liquid level sensor is arranged on the liquid level detection device; each centrifugal pump water diversion assembly is connected with the access where the liquid level detection device is located through opening-closing valves; an air pressure detection device is arranged outside the vacuum box. According to the vacuum centralized water diversion system for the ship, the multiple centrifugal pumps are controlled to conduct water diversion through the automatic control device according to the water values detected by the liquid level detection device, and finally simultaneous water diversion of the multiple centrifugal devices is achieved.