Auxiliary device for assembling and welding steel truss girder of cable-stayed bridge

The invention relates to the technical field of steel truss girder assembling and welding, in particular to a cable-stayed bridge steel truss girder assembling and welding auxiliary device which comprises a mounting base and a hollow stand column, the hollow stand column is fixedly connected to the surface of the mounting base, a positioning plate is fixedly connected to the interior of the hollow stand column, and a first screw rod is rotationally connected to the surface of the positioning plate; the surface of the first screw rod is sleeved with a screw sleeve in a threaded mode, the surface of the screw sleeve is fixedly sleeved with a hollow moving column, the hollow moving column is inserted into the hollow stand column, the hollow moving column is slidably connected with the hollow stand column, and the bottom end of the first screw rod is fixedly connected with a first bevel gear. The hollow moving column is utilized and matched with the jack for jacking, so that the supporting disc and the supporting