The invention discloses a central air-conditioning refrigerating system for a ship. The central air-conditioning refrigerating system for the ship comprises air inlets, air outlets and refrigerating devices, wherein the air inlets, the air outlets and the refrigerating devices are arranged in all cabins correspondingly. Each refrigerating device is connected to the corresponding air inlet through a pipeline, an inner cavity of each air inlet is provided with a servo motor, an impeller is arranged at the front end of each servo motor, an electromagnetic valve is arranged at a port of each air inlet, each servo motor and the corresponding electromagnetic valve are both electrically connected to a controller of the corresponding cabin, and each controller controls the rotating speed of the corresponding servo motor so as to adjust the air flow of the corresponding cabin and controls the corresponding electromagnetic valve to start and stop pipeline ventilation. Exhaust fans are arranged in inner cavities of the air outlets and connected to the outer side of a hull through pipelines. The central air-conditioning refrigerating system for the ship has the beneficial effects that the temperature can be automatically and manually adjusted for the different cabins, refrigerating and ventilating effects are good, energy is saved, and environment friendliness is achieved.