The invention discloses a spirally-formed X80 steel grade main riser. The main riser comprises the chemical components of, by mass, 0.04-0.08% or less of C, 0.15-0.35% of Si, 1.55-1.85% of Mn, 0.012% or less of P, 0.004% or less of S, 0.15-0.30% of Ni, 0.15-0,30% of Cr, 0.10-0.30% of Cu, 0.15-0.30% of Mo, 0.03-0.06% of Nb, 0.06% or less of V, 0.06% or less of Ti, 0.04% or less of Al and the balance Fe and inevitable impurities, wherein the carbon equivalent Ceq is equal to or less than 0.45%, and CEpcm is equal to or less than 0.22%. The main riser adopts a hot rolling coiled plate as a raw material, and a composite fine-crystal structure combining a needle-shaped ferrite and a bainite is adopted as the main structure. The spirally-formed X80 steel grade main riser is high in strength and dimensional precision and has excellent comprehensive properties such as the anti-fatigue property, the anti-fracture property and the anti-corrosion property.