Abstract: In allusion to the West-to-East Gas Transmission Pipeline Project, the article points out that it is uneconomical and unpractical to lay new natural gas pipeline in the city with large population and dense buildings.An economic and feasible method is to transmit natural gas using original gas pipeline networks. The authors introduce a sort of high-powered polyurethane-polyethylene glycol terephthalate (PET) fiber fabric-aluminum foil composites liner to be used as airtight joint structure of the gas pipeline, also the gas pipeline reconstruction technology "Nordi-Part" of Chevalier-PRS (Asia) Holding Ltd.in Hongkong.The test on the air-tightness, air pressure resistance, bending and peel strength, accelerated aging of the gas pipeline airtight joint structure is made.The results show that the structure has excellent property, reliability and can be suit for the reconstruction of the city gas pipeline in the West-to-East Gas Transmission Pipeline Project.