Abstract: Aiming at the different commissioning time of Jiangxi Branch Pipeline and Trunk-line in Sichuan Gas-to-East Transmission Pipeline, the design scheme and safety measures about the extension facilities of Initial Station of Jiangxi Branch Pipeline tiedin with the venting pipeline and drainage pipeline in stations along the Trunk-line are provided. The nitrogen sealing scheme before commissioning of the Branch Pipeline is that the offtake pipeline section and branch pipeline section in the Branch Pipeline in Huangmei Station of Jiangxi Branch Pipeline are sealed with nitrogen, respectively. The operation procedure is as follows: flowrate of gas is regulated with valve, nitrogen is replaced and pressure of gas is raised. The gas transmission process in the Initial Station is changed based on the 2-stage flow regulation, and gas-push-nitrogen and gas pressure increasing are completed. The monitoring data after commissioning show that the nitrogen displacement is reasonable and the scheme is doable.