The utility model discloses a dehumidification heat sink of cubical switchboard, including the cubical switchboard body, the dehumidification mouth has been seted up at the top of cubical switchboardbody, be equipped with the air exhauster in the dehumidification mouth, the air outlet of air exhauster is connected with the tuber pipe of slope, the air -out union coupling has the axis to be vertical spiral coil, the air -out union coupling is in the bottom of spiral coil, the switch cabinet comprises a switch cabinet body, the exit linkage of drainage tube has the header tank, the export of drainage tube is provided with first check valve with the junction of header tank, the cubical switchboard body is provided with the cooling coil with the laminating of cubical switchboard body outward,cooling coil's water inlet is connected with the delivery port of header tank, cooling coil's delivery port is connected with the drain pipe, this internal humidity transducer that is provided with of cubical switchboard, humidity transducer connects the air exhauster, the utility model provides a can the automatic dehumidification heat sink of cubical switchboard who dehumidifies the cooling.