The device is composed of two sets of lifting conveyors, a set of lifting mechanism and two sets of transiting mechanisms. Firstly, according to the thickness of an irradiated object and the height of the adjusting conveyor table of the lifting mechanism, the irradiated object is allowed to keep an optimal irradiation distance when passing through an electron beam, the irradiated object is conveyed to the part under the electron beam by a trigger bar, and then transmitted to the trigger bar by a transiting roller, and because the special slit transiting mechanisms is adopted, the problems that a metal machine frame is directly irradiated by the electron beam to lead the metal machine frame to generate heat and noxious gas can be solved. In addition, both power and detection devices of lifting and traveling are arranged outside the irradiation zone, thereby the reliability of the equipment is greatly enhanced.