Roller vacuum dryer

The utility model discloses a roller vacuum dryer which comprises a roller drying bin, a roller path, a gear ring, a three-way device, an elbow device, a discharge valve, a vacuum unit, a riding wheel, a support and a driving device. The roller drying bin comprises a heat preservation bin and a drying bin; the drying bin comprises a roller, a metal cover, a heating pipe, a heat conduction pipe anda spiral blade. To-be-dried materials outside the drying bin of the roller drying bin enter the drying bin through a discharging valve on a feeding port of a three-way pipe of a three-way device on abin inlet of the drying bin of the roller drying bin. A heat conduction medium conducts heat conduction and heating in the metal cover and the heating pipe, the conduction speed of heat energy is increased, and the vacuum unit pumps and exhausts air in the drying bin and moisture generated during material drying; the collision contact rate and the heat conduction area with materials are increasedby rotating the heating pi