The test of tensile, impact and low temperature drop weight tests on X65MO steel 22. 2 mm and 24. 0 mm plates, ϕ558. 8 mm pipes and welded joints and the analyzing on structure and performance have been carried out. Through thermomechanical controlled rolling and cooling technology, i. e. the thickness of the billet to be warmed is 88 mm, the re¬duction ratio is greater than 10, the second beginning rolling temperature is set to 870 ~880 ℃ , and the final rolling temperature is set to 820 ~ 830 ℃ , using ultra-fast cooling for cooling i. e. the inlet water temperature is set to 750 ~760 ℃ and the final cooling temperature is 460 ~ 500 ℃ , the mixed structure of ferrite and bainite is obtained, the ferrite content is 50% ~ 60% , and the strength and toughness of pipeline steel pipe meet the customer requirements.