The invention relates to a dehumidifying device for security inspection equipment. The dehumidifying device comprises a cold conducting plate, a semiconductor chilling plate, an orientated air discharging system and a water storage box, wherein the semiconductor chilling plate is arranged between the orientated air discharging system and the cold conducting plate; and the water storage box is arranged below the orientated air discharging system. The dehumidifying device for the security inspection equipment has the advantageous effects that the structure is simple and the operation is simple and convenient; and the dehumidifying device can be used for dehumidifying the security inspection equipment in various environments, can work stably and has a long service life.