The invention relates to a production method of X80 thick-specification ultra-wide longitudinal submerged arc welding pipeline steel. The thickness of a finished product of the longitudinal submergedarc welding pipeline steel is larger than or equal to 25 mm, and the width of the longitudinal submerged arc welding pipeline steel is larger than or equal to 4400 mm; and the production process routeof the longitudinal submerged arc welding pipeline steel comprises the steps of molten iron pretreatment, converter smelting, external refining, Ca treatment, continuous casting, slab heating, rolling, TMCP controlled cooling and straightening, wherein an LF + VD refining or RH refining method is adopted in the external refining, the heating time and the temperature of the high-temperature section are controlled during slab heating, three-section type control rolling is adopted in the rolling process, holding delay is carried out twice in total, in the TMCP cold control process, an ACC controlled cooling system is adopted for cold controlling, and three passes of straightening are adopted in the straightening process. According to the production method of the X80 thick-specification ultra-wide longitudinal submerged arc welding pipeline steel, existing equipment, blank conditions and technical conditions are utilized, the thick-specification ultra-wide longitudinal submerged arc welding pipeline steel meeting the product performance requirement can be produced, and the product quality is stable.