Construction device for high-altitude welding of large-section box girder

The utility model discloses a construction device for high-altitude welding of a large-section box girder, which comprises a sliding component, a sliding component and a lifting component, the sliding component comprises a sliding frame and two sliding wheel sets, the sliding frame stretches across the top of the box girder, and the two sliding wheel sets are arranged on the bottom surface of the sliding frame; the sliding wheel set comprises two sets of sliding wheels which are arranged in the length direction of the box beam in a spaced mode. The two sides, in the width direction of the box beam, of the sliding frame are both exposed out of the box beam. The two suspension cages are connected to the two sides, exposed out of the box-shaped beam, of the sliding frame respectively and located below the sliding frame. The sliding assembly stretches across the tops of the two wing plates, and the two lifting cages are installed on the two sides, in the width direction of the box beam, of the sliding assembly re