The high-temperature air in the heat pump drying room transfers heat to the wet material, so that the temperature of the wet material rises, and the moisture contained in it evaporates, thereby realizing the drying of the wet material. There is a double-layer material plate in the cylinder, which could continuously picks up and throws the material, so that the material is fully contacted with the hot air, which promotes heat exchange and makes the material move from front to back. The dried slag is discharged out of the drying drum through a sealed screw conveyor, and then packaged manually. The waste gas is discharged into the atmosphere from the chimney after being treated by the dust removal device.