Heat exchanger back flush device

The utility model provides a heat exchanger back flush device which comprises a boiler wall, a heat exchanger, a first water outlet, a first water inlet, a second water inlet and a second water outlet, wherein the heat exchanger is arranged inside a boiler, and the first water outlet, the first water inlet, the second water inlet and the second water outlet are formed in the boiler wall. The heat exchanger back flush device solves the problems that in the prior art, a cooling effect is low and washing is difficult caused by scale depositing of the boiler exchanger.