Support for steel structure welding

According to the support for welding the steel structure, the upper surface of a first base is fixedly connected with a first lower clamping plate, a first upper clamping plate is attached to the first lower clamping plate, a second lower clamping plate is placed on a second base, and a second upper clamping plate is attached to the upper surface of the second lower clamping plate; bolts are arranged at the four corners of the first upper clamping plate and the four corners of the second upper clamping plate. According to the utility model, through the arrangement of the measuring mechanism, the bottom end of the arranged measuring rod can be attached to the upper surface of one of the steel structures, when the two steel structures are in butt joint and the fixed sleeve is controlled to slide randomly in the sliding hole, the bottom end of the measuring rod can slide on the upper surfaces of the two steel structures, and if the two steel structures do not have dislocation difference, the two steel structures