Self-propelled platform and method suitable for construction of small-angle oblique crossing overpass bridge

The invention provides a self-propelled platform and method suitable for construction of a small-angle oblique crossing overpass bridge. The facility comprises a walking track arranged between skewbacks on the two sides. The walking track is laid in the longitudinal direction of the bridge. The sliding platform is installed on the walking track in a sliding mode through supporting legs, and a detachable arch rib assembling support is arranged on the sliding platform. A plurality of jacking and position adjusting devices are arranged at the top of the arch rib assembling bracket. When in use, the arch rib is hoisted at the top of the assembly bracket, and the two ends of the arch rib are fixedly connected with the skewback by adjusting the jacking and positioning device; the arch ribs are sequentially hoisted in the longitudinal direction of the bridge, and the arch ribs are connected through temporary supports; the arch ribs are permanently connected, the assembling supports are disassembled, and the box gird