Ultra-low bridge girder erection machine

The invention discloses an ultralow bridge girder erection machine, and belongs to the technical field of bridge girder erection machine equipment. The ultralow bridge girder erection machine is characterized in that a winch unit is arranged in a vehicle body structure, and a middle supporting leg walking wheel assembly is arranged in a middle supporting leg walking cross beam, so that the effectthat the overall height is reduced to 4.91 m is achieved; the lower parts of a left middle supporting leg reverse roller set and a right middle supporting leg reverse roller set are integrated with the upper end part of the joint of a middle supporting leg walking cross beam, so that the effect of reducing the overall height between the left middle supporting leg reverse roller set and the middlesupporting leg walking cross beam and the overall height between the right middle supporting leg reverse roller set and the middle supporting leg walking cross beam are achieved; a left hydraulic lifting cylinder is arranged o