The utility model discloses a cargo airplane tail backwater device, pass through the return water pipeline and connect with the aircraft nose water tank of setting in aircraft nose department, tail water tank and aircraft nose water tank including setting up the tail water tank of locating at the tail. A cargo airplane tail backwater device, two water pumps each other are reserve, and a trouble can be opened for one immediately, but the height of water -level switch automated inspection water level, and then the operating condition of control pump, the aircraft nose water tank is got to with water to the tail, and pump station spraying water tank is sent together to water and cooling water that the aircraft nose water tank was responsible for coming the tail, realizes cyclic utilization, in addition, the device simple structure, it is with low costs, easily promote.