The main component of a two-stage compression screw air compressor is two-stage air end compression, and the compression process consists of a first stage air end and a second stage air end compressed in series through grading. The two-stage screw air compressor not only inherits the advantages of the two-stage screw compressor, such as simple structure, flexible installation and high efficiency, but also highlights its own advantages of high efficiency and energy saving: it can reduce bearing load and improve Volumetric efficiency; Under some load operating conditions, it can improve efficiency and save energy; Compared with ordinary screw air compressors, two-stage screw air compressors can save 150% energy. If each unit operates for 8000 hours per year, it can save a lot of electricity bills annually.