The utility model belongs to the technical field of the pipeline washs, aim at providing a send out spray gun for washing of head of an electric machine water box and have belt cleaning device of thisspray gun, this spray gun includes nozzle and hollow connecting piece, spray tube and locating part, the utility model provides a spray gun, to the structure of sending out head of an electric machine water box, serve in the grafting of connecting piece through cup jointing the nozzle activity, the spray tube cup joints on the link of connecting piece, and on locating the connecting piece with the one end of locating part, the other end cup joints on the lateral wall of nozzle, when the orifice punch combination of high -pressure liquid stream process spray tube in proper order and connectingpiece follow nozzle does not have the dead angle blowout, the nozzle is continuously done 360 down at the drive of orifice punch combination and the combined action at each first through -hole and isrotated in connecting piece and locating part spacing space, therefore, can thoroughly clear away corruption deposit or result in the stifled generator water loop of dying, thoroughly solve blockagefault, the cleaning efficiency is high, good stability, simple structure is compact and with low costs, and wide practicability.