Abstract: For the first time in China, ϕ1 422 mm×80 mm steel pipes with the thinnest wall thickness of 21.4 mm were used in the construction of the China-Russia Eastern Natural Gas Pipeline Project. The technical scheme of groove forming machine for ultra-large diameter oil and gas pipeline pipe was introduced in detail. Several key technologies to ensure the groove machining accuracy were analyzed. The integrated positioning, clamping synchronous technology and floating cutting technology are putting forward to ensure positioning accuracy and cutting accuracy of the machine tool setting during groove machining. The field application shows that the machine is reasonable in design and stable in running performance.