The vacuum dryer is a device that removes moisture from the parts inside the container by pumping out the air inside the packaging container to reach a predetermined vacuum degree. During the drying process, the inside of the tank is in a vacuum state, and the jacket is heated by hot water (or steam, heat transfer oil). As the tank rotates at a low speed, the material moves up and down in the tank, forming a "diamond track" inside and outside the tank and absorbs evaporation. The steam is continuously discharged through the vacuum pipeline to achieve the purpose of drying the material. While drying the mixture, built-in spraying, filtering, crushing and other devices according to customer requirements can realize its multi-functional operation.