Abstract: In this paper, the Trans-Asia Gas Pipeline was optimized in terms of piping mode, fitting optimization, equipment selection and pipeline installation based on the project characteristics. A series of optimization designs were conducted for the following parts, including burying of pipeline crossing saline area instead of laying in aboveground embankment, line ballast tank, replacement of fire bending elbows with cold elbows, micro-turbine generators, stress at pigging stations, methanol injection points at valve rooms and pigging stations and condensate collectors. After optimization, the pipeline system reached international advanced level in terms of each technical indicator. Based on the optimization design, the investment was reduced and the operation safety and reliability of the pipeline were improved. Furthermore, the construction period was shortened, so the pipeline was put into operation as scheduled. It provides valuable experience for the optimization design of similar gas pipeline projects in the future.