Microwave vacuum dryer is a new type of microwave energy application equipment combining microwave energy technology and vacuum technology. It has a series of advantages of microwave and vacuum drying, and overcomes the shortcomings of conventional vacuum drying such as long cycle and low efficiency. In the drying process of general materials, the work efficiency can be increased by 4-10 times compared with the conventional method. Microwave vacuum drying equipment is a high-tech product integrating electronics, vacuum, mechanics, thermodynamics, program control and other disciplines. It is a new technology and process developed on the basis of in-depth research on physical changes of substances, internal and external heat and mass exchange and moisture transfer process under vacuum conditions.