The present invention discloses a dehumidification device of a high-voltage electric cabinet. The device comprises an electric cabinet box. The top of the electric cabinet box is fixedly connected with a box body, the middle of the box body is provided with a screw rod, the screw rod penetrates the box body and extends to the inner part of the electric cabinet box, and a fixing block sleeves the surface of the screw rod. The right side of the fixing block is provided with a motor, the output shaft of the motor is fixedly connected with a rotating rod, the rotating rod is fixedly connected witha gear matched with the screw rod, and the fixing block is used for allowing the gear and the screw rod to fit tightly. According to the dehumidification device of the high-voltage electric cabinet,by providing a humidity sensor and a control switch, and by using the motor, the screw rod, the gear, a moving plate, a air exhaust fan and compression springs, the linkage relations between the motor, the screw rod, the gear, the moving plate, the air exhaust fan and the compression springs are formed, and wet air in the electric cabinet is exhausted; by using the dehumidification fan, the wet air is exhausted from an air and water outlet hole, so that the internal drying is ensured, the humidity in the electric cabinet is controlled within a safe range, and the production of condensation isavoided.