The utility model discloses a cable water-cooling device, which is composed of a cable and a water-cooling pipe, wherein the water-cooling pipe is communicated with a water pump and a cooling device, a water pump controller is electrically connected with the water pump and the cooling device and controls the water flow velocity and /or temperature through adjusting the water pump or the cooling device, and the water-cooling pipe and the cable are adjacently arranged. The water-cooling pipe and the cable are adjacently arranged in perallel, or the water-cooling pipe is winded on or stuck to the cable. The cable water-cooling device also can be provided with a speed sensor and/or a temperature sensor arranged on the water-cooling pipe. The cable water-cooling device has the advantages that because the cable water-cooling device takes the water cooling measures, the working temperature of the cable is decreased, therefore, the current-carrying capacity of the original cable can be improved, and the requirement of load is met, and simultaneously, the operating life of the original cable is prolonged.