Overhead cast-in-place box girder flange plate formwork system

The invention relates to an elevated cast-in-place box girder flange plate formwork system, and relates to the field of bridge engineering, the elevated cast-in-place box girder flange plate formwork system comprises a box girder body erected at a supporting steel frame, the box girder body comprises a web plate, a supporting plate, a cantilever plate and a bottom panel which are integrally formed, and the supporting steel frame is provided with the formwork system; the formwork supporting system comprises a connecting piece, a movable sleeve rod, a lifting rod, a supporting plate and a cantilever supporting plate, the cantilever supporting plate is attached to the inclined face of the cantilever plate, the movable sleeve rod is connected with the connecting piece, the lifting rod is inserted into the movable sleeve rod and is in threaded connection with the movable sleeve rod, and the end, away from the connecting piece, of the lifting rod is rotationally connected with the supporting plate. The supporting d