Compressed air is the most important energy resource for present industrial production and automated control equipment, because of its economy, feasibility and reliability. However, the oil, oisture, dust and other impurities in compressedair would damage air equipment operation, resulting in high maintenance costs, or even directly influence on the quality of products. With continuous improvement of industrial automation, manufacturing enterprises have more and more highly requirements of air quality. Compressed air dry filter is widely used in manufacturing enterprises, such as automobile, electric power, chemical, pharmaceutical, food, plastics and so on. In particular, it is absolutely necessary air filtration equipment for factory automation equipment and laboratory instruments which have high quality requirements of air.