The invention relates to a water cooling metal tube resistor. The water cooling metal tube resistor includes a water pump, a water tank, a water inlet main pipe, a water outlet main pipe, an insulation support assembly and multiple S-shaped continuous curved metal pipes, wherein the metal pipes are supported by the insulation support assembly, ports of the metal pipes are in insulation communication with the water inlet main pipe, the other ports of the metal pipes are in insulation communication with the water outlet main pipe, the water tank is filled with the non-conductive deionized water,the water pump is in communication with the water inlet main pipe and the water tank, and the water outlet main pipe is in communication with the water tank. The metal pipes are taken as resistors, during operation, the deionized water in the water tank driven by the water pump is circulated sequentially through the water inlet main pipe, the metal pipes, the water outlet main pipe and the watertank, the deionized water is in direct contact with inner walls of the metal pipes, heat is transferred directly to the deionized water and taken away without the need for a traditional insulation layer, and the cooling effect is better.