Gantry type welding workstation

The utility model provides a gantry type welding workstation. The gantry type welding workstation comprises a first positioner, a second positioner, a logistics trolley and a welding robot system. Each of the first position changing machine and the second position changing machine comprises a gantry framework, a lifting driving device, a hydraulic balance mechanism, a lifting cross beam and an overturning arm of an L-shaped structure; a crawling ladder is arranged on the side surface of the gantry framework; a fixing clamp is mounted at the tail end of the overturning arm; the hydraulic balance mechanism connects the lifting cross beam with the gantry framework through a chain and chain wheel mechanism; the first positioner further comprises a driving mechanism and a ground rail; by means of the gantry type positioner structure and automatic clamping of the workpiece to be welded, an existing manual clamping mode is replaced, the labor intensity of workers is reduced, and the welding operation efficiency is i