The invention discloses an energy-conservation and environmental-protection smoke absorption welding gun. The energy-conservation and environmental-protection smoke absorption welding gun consists ofa welding gun main body and a smoke purifying device, wherein the welding gun main body comprises a gun body, a protective gas guide pipe, a welding wire guide pipe, an electric conducting nozzle, a smoke channel, an adjustable elbow, a dust collecting cover, an insulation material support structure in the dust collecting cover, an exhaust hose, a welding gun cable, an air volume adjusting switch,a power supply switch, a welding wire guide pipe joint, a power supply joint, a protective gas guide pipe joint and an exhaust hose joint. As the dust collecting cover with a specific type and capable of moving front and back is arranged at the front end of the welding gun, and the air volume adjusting switch is arranged on the welding gun, after electric welding smoke is collected by the dust collecting cover, the electric welding smoke is fed in the smoke purifying device after passing through the smoke channel in the gun body of the welding gun and the exhaust hose sleeved with the weldingcable inside, and is filtered and purified for emptying, when the welding process and the welding quality are guaranteed, the electric welding smoke is efficiently collected, and the concentration ofthe electric welding smoke in an operation field is reduced.