The utility model belongs to the technical field of lithium ion battery production equipment, and particularly relates to an oven device of a coating machine. The oven device comprises an oven, upper-row air nozzles, lower-row air nozzles, an exhaust fan and an air blower; the oven is provided with a pole piece inlet and a pole piece outlet, the upper-row air nozzles and the lower-row air nozzles are oppositely arranged in the oven, accommodating rooms are arranged among the upper-row air nozzles and the lower-row air nozzles, and pole pieces can pass through the accommodating rooms; the exhaust fan is connected with the upper-row air nozzles by an exhaust pipeline; and the air blower is connected with the lower-row air nozzles by an air inlet pipeline, and a heating device is disposed at an inlet of the air inlet pipeline. Compared with the prior art, the oven device has the advantages that the exhaust fan performs exhaustion for the upper-row air nozzles to generate negative pressure, so that the pole pieces can pass through the accommodating rooms without being supported by carrier rollers; and hot air is fed into the lower-row air nozzles via the air blower, and is sprayed out of the lower-row air nozzles to directly heat wet coated layers and remove solvents in the wet coated layers, so that the pole pieces, which are provided with the wet coated layers, of back surfaces of substrates can be dried in a nondestructive manner.