Transverse movement supporting system of precast beam erection construction machine and construction method

The invention relates to a transverse movement supporting system of a precast beam erection construction machine and a construction method. The supporting system is structurally characterized in thata plurality of sets of lattice type shaping jig frames are fixed to a concrete strip-shaped foundation below; the adjacent lattice type shaping jig frames are connected into a whole through connectingpieces; four steel pipe stand columns on each set of lattice type shaping jig frame are welded to two long double-spliced H-shaped steel main beams in the transverse bridge direction; and longitudinal-bridge-direction short H-shaped steel distribution beams are welded to the two long double-spliced H-shaped steel main beams in the transverse bridge direction at intervals, and a guide rail beam isfixed to the multiple longitudinal-bridge-direction short H-shaped steel distribution beams in the transverse bridge direction. A front supporting leg of the precast beam erection construction machine is placed on a front span