Dry screw vacuum pump is a high-tech product, and its manufacturing difficulties focus on the design and processing of two screws. Screw rotor, the core component of screw vacuum pump, is a three-dimensional structure, so it is necessary to design and solve a three-dimensional curved surface mathematical model in the R&D design of screw. The solid machining formed by three-dimensional mathematical model needs to be processed on five-axis numerical control equipment, which is expensive, and the import of this equipment is also restricted by the technical blockade of developed countries. In order to be able to process on domestic 3D CNC equipment, it is necessary to transform the 3D solid surface model equation into a 2D mathematical model with a cross section through Fourier transform before it can be applied to the actual production and processing process. The whole design and machining process of screw vacuum pump is an extremely complicated theoretical solution and NC machining process with high technical content. At the same time, the overall control of screw pump also involves many technical fields such as optics, machinery and electricity. Because of the technical characteristics of screw vacuum pump, the twin-screw rotor is used to form vacuum, so it has incomparable technical advantages compared with other vacuum obtaining equipment.