The invention discloses a dehumidification device for a distribution box with a vertical low-resistance cooling system, which comprises a main box body and a first storage compartment, and a refrigeration device is arranged in the first storage compartment; a humidity sensor and a temperature sensor are arranged inside the main box body , main controller, exhaust fan, heater and heat exchanger, humidity sensor, temperature sensor, exhaust fan, heater and refrigeration device are all connected with the main controller, heat exchanger includes outer tube and heat exchange tube, heat exchange tube Placed in the outer tube, the two ends of the heat exchange tube are connected with the refrigerant inlet and the refrigerant outlet. A water storage container and a drain pipe are provided, and the top of the water storage container communicates with the drainage funnel. In the present invention, the middle surface of the heat exchange tube is provided with multi-layer and multi-row linear bending heat exchange parts, so that the effect of heat exchange, refrigeration and dehumidification is better, and the water vapor in the humid air is discharged through the drainage funnel after being condensed at the heat exchange tube. Thereby keep the dryness of the air in the main cabinet.