The invention discloses a method for producing a JCOE longitudinal submerged arc welded pipe of an X80 pipeline steel. The invention is used for producing an oil and gas conveying tube with high intensity and high tenacity. The method includes using an HTP X80 controlled rolling steel pipe with a chemical composition of 0.03 to 0.05 percent of C, 0.20 to 0.30 percent of Si, 1.65 to 1.75 percent of Mn, less than or equal to 0.01 percent of P, less than or equal to 0.005 percent of S, 0.10 to 0.15 percent of Nb plus Ti and 0.5 to 0.7 percent of Ni plus Cr plus Cu. A steel plate is made into the oil and gas conveying tube with high intensity and high tenacity through the working procedures like edge milling, edge bending, a 'JCO' forming technique under multi-pass pressing, gas protection prewelding, inside welding, outside welding, diameter enlarging, ultrasonic checking, x-ray checking, hydraulic pressure testing, tube end to arris, ultrasonic checking and X-ray checking, etc. The inside welding and the outside welding of a steel tube adopt four-wire serial union melt welding and control the technical parameters of welding through selecting a suitable welding wire and a welding fluid; thereby controlling the components and organizations of a weld joint to lead the performance of the weld joint to reach the performance requirements of X80.