The utility model relates to an overhead type cubical switchboard evaporation dehumidifier, it includes the casing, inside first baffle and the second baffle of casing is first cavity, second cavity and third cavity with inside once the partition from left to right of casing, first vent has been seted up to first cavity bottom, and first vent department is provided with the fan, is provided with humidity transducer in the first cavity, second cavity bottom sets up second vent, the inside heating evaporation dehydrating unit that is provided with of second cavity. The utility model discloses simple structure, reasonable in design, installation convenient to use can effectively solve the moist problem of the interior air of automatically controlled cabinet to having overcome traditional dehumidifier and having installed at automatically controlled drainage problems cashier's office in a shop, the equipment belt that results in dehumidifying comes the potential safety hazard scheduling problem, and the practicality is strong, excellent in use effect, convenient to popularize and use.