Abstract: The harsh marine environment typically demands that the submarine oil and gas pipelines possess high strength and toughness,and good weldability. And under certain extreme conditions like some severe submarine cliff area,additional requirements for large-deformation resistance are put forward. To meet the technical specifications of a certain African marine pipeline project,a high-performance DNV SAWL 450 FDPR SAWL pipe is developed. Elaborated here in the paper are the main aspects of the said submarine service pipe,including the chemical composition and the mechanical properties of the anti-large deformation steel plate,the technical requirements of the above mentioned submarine pipeline project,the welding formation technology and the product properties of the anti-large deformation SAWL pipe for deep sea service. The R & D results demonstrate that after 1.5% longitudinal strain and aging at 250 ℃,the impact energy at-31 ℃at both the mid-thickness weld and the fusion line of the trial pipe samples,as well as the CTOD value of the weld at -21 ℃significantly exceed the project’s technical requirements. The pipe as developed exhibits both excellent plasticity and low-temperature toughness after being largely deformed,having been suitable for harsh deep-sea environment service as requiring large-deformation resistance.