The invention relates to a 3000t special bridge girder erection machine for integrally erecting a 120m-span double-layer four-line steel beam bridge for highway and railway, which is characterized by comprising a bracket structure (1), a lower guide beam structure (2), a roller group (3), a front end rack winch (4) and a matched beam conveying vehicle (5). The invention creates a construction method and special equipment for integrally erecting a long and large steel bridge with large span and cross section and dead weight, greatly shortens the construction period of the long and large steel beam bridge, greatly saves construction funds, and develops a new construction technical direction for the construction of the steel beam bridges.