The invention discloses energy-saving steel structure welding equipment, and belongs to the technical field of steel structure welding. The energy-saving steel structure welding equipment comprises asliding rail, the top of the sliding rail is slidably connected with a portal frame, the top of the portal frame is slidably connected with two positioning blocks, and the tops of the positioning blocks are provided with cleaning devices for treating smoke dust and gas extracted by exhaust pipes; the cleaning devices comprise positioning boxes fixedly arranged at the tops of the positioning blocks, exhaust fans are fixedly arranged at the ends, away from the exhaust pipes, in the positioning boxes, a heating assembly, an absorption assembly and a detection device are sequentially arranged in each positioning box, air discharging pipes are fixedly arranged at the ends, away from the exhaust pipes, of the positioning boxes, first electromagnetic valves are fixedly arranged on the air discharging pipes, circulating pipes are fixedly arranged at the positions, located on the air discharging pipes, of the positioning boxes, the ends, away from the exhaust pipes, of the circulating pipes extend into the positioning boxes and to the sides, away from the absorption assemblies, of the heating assemblies, and second electromagnetic valves are fixedly arranged on the circulating pipes. The equipment has the effect of reducing the emission of toxic gas carbon monoxide into the air.