Freeze dryer, also known as freeze-drying machine, is a device that uses low-temperature freezing and sublimation processes to remove moisture from materials. Freeze drying machines are widely used in the production and preservation of industries such as pharmaceuticals, food, cosmetics, and traditional Chinese medicine. The freeze-drying process includes three stages: pre freezing, sublimation drying, and analytical drying. The freeze-drying machine mainly consists of a material freeze-drying bin, a water-cooled condenser, a refrigeration system, a vacuum system, a heating system, an electrical control system, etc.