The invention discloses a manufacturing method of an X100-stage pipeline steel large-diameter spiral submerged arc welded pipe. The manufacturing method comprises the working procedures of uncoiling,flattening, edge milling, forming, prewelding, internal and external finish welding, pipe end diameter expansion, X-ray continuous detection, hydrostatic testing, ultrasonic flaw detection of a weld joint and a base material, pipe end chamfering, pipe end shooting and finished product detection. In the welding working procedures of the manufacturing method, a prewelding technology is added beforeinternal and external finish welding, continuous prewelding can be conducted on the overall length of the weld joint, and the forming and weld joint quality is ensured. In the welding working procedures, welding technological parameters are reasonably selected, the welding heat input is strictly controlled, meanwhile, self-developed special high-toughness submerged arc welding wires and sintered fluxes are selected for use, thus a weld joint structure obtains an evenness structure with acicular ferrites and bainite as priority, and toughness matching of welded pipe welding connectors and the weld joint quality can be ensured. The X100-stage large-diameter spiral submerged arc welded pipe produced through the manufacturing method has the characteristics of being high in strength, excellentin impact toughness and small in residual stress, and is suitable for being used in a large-throughput oil and gas pipeline with the delivery pressure being 12MPa or more.