The invention discloses an X80-level straight seam submerged-arc welded pipe with hydrogen sulfide stress corrosion resistance as well as a manufacturing method thereof. The straight seam submerged-arc welded pipe comprises a welding seam and a welded pipe body, and is characterized in that the welded pipe body consists of the following elements in percent by mass: not greater than 0.04% of C, 0.20%-0.40% of Si, 1.20%-1.80% of Mn, not greater than 0.008% of P, not greater than 0.002% of S, 0.10%-0.30% of Ni, not greater than 0.15% of Cr, not greater than 0.15% of Cu, 0.01%-0.10% of Nb, 0.01%-0.10% of Ti, 0.10%-0.30% of Mo, 0.04%-0.10% of Al, not greater than 0.0005% of B, not greater than 0.002% of Ca, and the balance of Fe and inevitable impurities. According to the X80-level straight seam submerged-arc welded pipe and the manufacturing method thereof disclosed by the invention, the X80 straight seam submerged-arc welded pipe disclosed by the invention has good strength, toughness, welding performance, ductility and corrosion resistance through reasonably deploying and controlling material components, a manufacturing process, a manufacturing technology and subsequent processing. Besides, high-pressure large-flow conveying requirements of oil gas under an acidic environment are satisfied.