In order to meet the requirements of fire-proof and explosion-proof, membrane separator, the key part of an aircraft fuel tank inerting system, has been widely used in foreign countries and in the development stage within china. Next, it will gradually be applied to military and civil aircraft. We analyze present situations at home and abroad, expound the working mechanism of the membrane separator, and discuss the membrane material, membrane fabrication technology and the membrane separator in detail. The main parameters affecting the performance of membrane separator are summarized. The experimental study on the application of the membrane separator in the air conditioning system was carried out. The results show our study is beneficial to the future development and application of the membrane separator.