The invention provides a drying device for panel processing. A plurality of horizontal hollow layers are arranged in a box body; each of air inlet branch pipes is connected with the corresponding horizontal hollow layer; a vertical hollow layer is arranged on the rear wall of the box body; the vertical hollow layer communicates with the horizontal hollow layers; two telescopic rods are fixed on the left side wall above each of the horizontal hollow layers; an inserting groove plate is arranged at one end of each of the telescopic rods; a plurality of left inserting grooves are formed in each inserting groove plate; and left support plates are inserted in each of the left inserting grooves. The drying device for panel processing disclosed by the invention has the beneficial effects that each of the air inlet branch pipes communicates with the corresponding horizontal hollow layer, the horizontal hollow layers communicate with the vertical hollow layer, and ventilation holes are uniformly formed in each of the hollow layers, so that thorough drying of a plank can be achieved; the telescopic rods are arranged in the box body, so that planks in different sizes can be dried; and the inserting grooves are formed in each inserting groove plate, and the inserting positions of the support plates can be selected according to the thickness of the plank.