Automatic opening alarm safety door

The invention discloses an automatic opening alarm safety door and belongs to the field of safety doors and new energy. The device is composed of a door plate, a door frame and an alarm, the alarm installed on the door frame is composed of a machine shell, a machine cover, a power panel, an exciter and a power generator, the exciter is composed of a sliding block, a main magnet, a guide pin, a buffer spring and an excitation spring, and the power generator is composed of a coil and an auxiliary magnet; a left cavity and a right cavity are formed in the machine shell, a cover cavity is defined by a cover plate of the machine cover and a cover ring frame on the cover plate, the sliding block is composed of a guide block and a shifting block, and a pin hole and a block sinking groove are formed in the guide block. The main magnet is embedded in the guide block, and opposite magnetic poles of the main magnet are alternately arranged along the axial direction of the pin hole; the machine cover is arranged at the e