Protection system in erection of elevated box girder

The utility model provides a protection system in the erection of an elevated box girder, which comprises a suspension beam suspended in the air and forming a suspension space; the hanger is positioned on the suspended beam main body, the segmental box beam is connected with the hanger, and the hanger and the segmental box beam form a first protection assembly; the hanging beam comprises symmetrically arranged hanging beam main bodies, an erecting part is formed on each hanging beam main body, and the lifting appliance is arranged on the erecting parts; a cross beam is arranged below the lifting appliance, and the two ends of the cross beam are connected with the suspended beam body to form a second protection assembly for protecting the lifting appliance. And the connecting piece penetrates through the section box girder and the existing building, the connecting piece is tensioned to form transverse tensioning force, the transverse tensioning force forms a protection face, and the protection face forms a thi