The invention discloses a descending bracket self-mobile model framework bridge fabrication machine, and relates to a bridge fabrication machine. A middle lifting point cross beam takes place and finishes primary blanking together with a C beam and a traveling trolley system, so that conversion of a stressing system from the lower part to the upper part is realized. The front end of a nose bridge is driven by a front supporting cross beam system to be jacked in place. A bracket is driven by the traveling trolley system to move out transversely, move longitudinally to travel and move transversely to take place. The middle lifting point cross beam and the C beam together finish secondary blanking, a middle lifting point cross beam lifting rod is removed, the mobile die framework moves transversely to open, moves longitudinally to travel, moves transversely to close and jacks in place, and the C beam 7 is removed; and finally concrete is poured. Thus, through stressing system conversion of the bracket, the traveling trolley system, the middle lifting point cross beam and the C beam, the use at construction sites of continuous beams at sites of intertidal zones, canyons, urban viaducts, river-crossing bridges and cross-sea bridges with limited construction conditions and high construction difficulty, where the auxiliary hoisting equipment cannot reach, can be realized.