Centered around the cutting of X80 high strength oil/gas pipelines,the status quo at home and abroad in the technology field was analyzed.The composition and working principle of drilling and milling machine were introduced,hydraulic drive scheme was designed.By field tests,the conclusion is that drilling and milling machine can be used to cut high strength oil/gas pipelines with on-line pipe cutting not folder knife,short cutting time and can cut X80 high strength oil/gas pipelines.