Abstract: In the light of the pigging and pressure testing before commissioning of Sebei-Xi'ning-Lanzhou Gas Transmission Pipeline, this paper describes trouble-shooting methods for the pigging and pressure testing process from the determination of pressure testing program, the specifications requirements of pressure testing equipments and materials, the selection and application of pigs, the separation of pressure testing section of pipe, and the influence of elevation to the pressure testing data. The corresponding suggestions are given according to the pressure testing conducted in China.