Abstract: According to the technical requirements of Saudi Aramco and the technical parameters of 5 000 mm hot plate mill in NISCO,, the alloying design and process parameters had been deliberately selected,and thus producing 260 mm×2 570 mm section blanks with uniform composition and excellent low-profile structure. Combing TMCP rolling process with ultra-fast cooling technology, fine and uniform fine-grained structure dominated by acicular ferrite had been achieved. The developed products have good mechanical properties and low temperature impact toughness. Through small batch rolling, production process technology was established. Now NISCO is capable of supplying extra-wide X70 M grade pipeline steel plates.