Abstract: It is confirmed that the commissioning technology with the "No pig but nitrogen, gas-to-nitrogen, and nitrogen-to-air" process and the gas replacement sequence of the "Pipeline route behind compressor stations " are economic, safe and reliable for large-diameter, high-pressure long-distance gas pipeline based on analyzing and summarizing the advantages and disadvantages as well as the adaptability of various commissioning technologies for long-distance gas pipeline in combination with the commissioning experiences in NG Pipeline Project from Sichuan to the East. The key technologies in the commissioning process, such as inspection prior to commissioning, nitrogen replacement, natural gas replacement, pipeline boosting, test gas supply, etc are analyzed, and the nitrogen injection facilities, nitrogen injection location, nitrogen injection quantity and nitrogen injection temperature, nitrogen injection speed and nitrogen sealing range for nitrogen replacement of pipeline commissioning are mainly discussed, which may provide a reference to the commissioning of newly-built large-diameter high-pressure natural gas pipeline at home and abroad.