The invention discloses a drying device, relates to the technical field of agriculture product harvesting, and is used for solving the problem that in the using course of a conventional drying machine, in order to thoroughly air-drying meal feeds, workers need to repeatedly overturn pressed meal, and sealing property between molecules of pressed meal granules can be destroyed, so that the pressedmeal cannot be compressed and compacted. The drying device comprises a mounting part, an air drying mechanism arranged on the mounting part and an adjusting mechanism for adjusting a wind outlet angleof the air drying mechanism, wherein the adjusting mechanism comprises a driving actuating rod, a driven actuating rod, a hinging piece for connecting the driving actuating rod with the driven actuating rod, a sliding sleeve, a left shaking plate, a right shaking plate, a shaking connecting rod, a first rotating shaft and a positioning bracket; and the left end of the shaking connecting rod is connected with the left shaking plate, and the right end of the shaking connecting rod is connected with the right shaking plate. According to the drying device provided by the invention, the wind outlet angle can be adjusted, after being subjected to squeezing and dewatering by a squeezing machine, the pressed meal keeps compressed and compacted, and the storing cycle is prolonged. The invention further discloses an application method of the drying device.