The invention discloses a high-overload transformer testing device for a transformer area. The device comprises a box body, wherein a box cover is hinged to one end of the box body; a host is fixed inside the box body; a plurality of terminals are arranged on the surface of the host; a printer, a key and a display screen are sequentially arranged on the host; and a cleaning mechanism is arranged at the bottom in the box cover. The invention further discloses a high-overload transformer testing method for the transformer area. The device and the method have the beneficial effects that by virtueof the designed cleaning mechanism, the convenience for placement of a cleaning brush is improved by means of a containing groove, so that the host is more conveniently cleaned by utilizing the cleaning brush, and the cleaning efficiency is improved; a stabilization mechanism is arranged on the containing groove, so that the cleaning brush is placed in the containing groove more stably; a dustproof mechanism is arranged on a terminal, so that a dustproof effect of the terminal is increased, and the dust accumulation in the terminal is reduced; and due to the arrangement of a connecting line,a removed dustproof plug can be placed more conveniently, and the loss of the dustproof plug due to separated design is reduced.