The invention belongs to the technical field of welding, and particularly relates to an efficient two-welded-seam submerged-arc welding technology for 10-18mm thick steel through flux-cored wires. Theefficient two-welded-seam submerged-arc welding technology comprises the steps that two-Y type welding grooves are designed, the truncated edge of each two-Y type welding groove is 5.0-7.0mm thick, the angle of the welding grooves is 32.5-40 degrees, and the depth of the welding grooves is 1.0-7.0mm; and welded seams on the front face and the rear face are welded though the welding wires with thediameter being 4.0mm, during welding, the heat input of the welded seam on the front face is 18-28kJ/cm, back gouging is not conducted before the welded seam on the rear face is welded, the heat input of the welded seam on the rear face is 25-35kJ/cm, and the portions, larger than or equal to 1.5mm, of the welded seam on the front face and the welded seam on the rear face are overlapped. According to the efficient two-welded-seam submerged-arc welding technology, aiming at the flux-cored wires, the heat input of the welded seam on the front face and the heat input of the welded seam on the rear face which are approximate are adopted, the performance of the welding heat affected zone is kept to be relatively uniform, back-gouging-free welding is conducted, meanwhile, root through welding is ensured, the heat input of the welded seam on the rear face is rarely increased, the size difference between the grooves in the front face and the rear face is small, the overall filling quantity ofthe welded seams is effectively decreased, accordingly, the cost is reduced, and the efficiency is improved.