Polymer separation membrane is a semi permeable membrane with selective permeation function. The semi permeable membrane, differential pressure, temperature gradient and concentration gradient or potential difference as the driving force, the liquid gas mixture, or a mixture of organic and inorganic solution separation technology compared with energy saving, high efficiency and clean characteristics, and is considered the major technical support of new technology revolution. The membrane separation process includes reverse osmosis, ultrafiltration, microfiltration, electrodialysis, electrodialysis, gas separation, pervaporation and membrane separation. Used to prepare separation, pervaporation and membrane separation. There are many kinds of polymer materials used to prepare membrane. Now the most used is poly, polyolefin, cellulose lipids and silicone, etc.. There are many forms of the film, the general use of flat film and air fiber. The popularization and application of polymer membrane can obtain huge economic and social benefits. For example, exchange membrane electrolytic salt can reduce pollution and save energy by ion: the use of reverse osmosis desalination and desalination, energy consumption than other methods are small; from the air oxygen enrichment can greatly improve the recovery rate of oxygen by gas separation membrane.