Bottom die supporting system for high-position cross beam of cable-stayed bridge

The utility model belongs to the technical field of bridge construction, and particularly relates to a bottom die supporting system for a high-position cross beam of a cable-stayed bridge, the bottom die supporting system is arranged on the inner side of an upper tower column and used for supporting a bottom die, and the bottom die supporting system is a net-frame-shaped frame supporting mechanism and comprises an upper supporting body, a lower supporting body and a side supporting body. The upper supporting body comprises a top beam, the lower supporting body comprises a bottom beam, and the side supporting bodies comprise side beams and inclined supporting beams. A lower supporting part is embedded in the inner side of the bottom end of the upper tower column, and the two ends of the bottom beam are detachably connected with the lower supporting part through bolts; the bottom ends of the side beams are hinged to the lower supporting part, the upper ends of the side beams are arranged on the top beam in a sl