Abstract: Several problems in conventional hot tapping activity of pipeline are common, like technical complexity, time-consuming and environmental pollution by pipeline medium venting, and these will be often encountered in field installation of bypass lines using conventional hot tapping technology for pipelines. Therefore, the original hot tapping technique and branch installation operations are optimized, and a kind of technology and equipment for quick installation of branch lines on the in-service pipelines is developed. Tee flange and piping are welded first and then welded with baffle cross together, so a baffle cross featured by integrated holes and branch lines is shaped, after that, branch line is introduced outside on the baffle, and ultimately branch line installation of in-service high-pressure oil/gas lines is fulfilled. The technology has been successfully used in multiple sub-projects of West-to-East Gas Pipeline Project, such as Lun'nan Gas Compressor Station, Dingyuan Gas Compressor Station and Chengdu-Deyang Gas Pipeline. The new hot tapping method can meet the needs of high-pressure oil/gas pipelines for branch line installation, and provide a set of more economic and feasible branch line installation technology to the pipeline hot tapping activity.