Circulating air structure of dryer

The circulating air structure comprises a base, a drying box divided into a feeding cavity and a high-temperature cavity is integrally connected to the base, an air bellow is integrally connected to one side outside the drying box, a fan is rotationally installed in the air bellow, an air inlet is formed in one side of the air bellow, and a heater is arranged on the air bellow. A heat removal pipeline communicating with the feeding cavity and the high-temperature cavity is fixedly installed outside one side of the drying box. By arranging the driving motor, the driving motor drives the first rotating shaft to rotate, when the first rotating shaft and the second rotating shaft rotate, hot air is blown into the feeding opening from the top end of the heat removal pipeline, materials which are just put in are dried through the hot air, and materials to be dried are preheated in the feeding cavity; and the materials are subjected to primary preheating and then high-temperature drying, primary hot air is used for