The invention discloses an erecting method and device for a container type railway overhead girder. A container type railway overhead girder can be loaded on a railway flat plate carrier vehicle and is directly conveyed to a plan erect position, and a back cover of a container is opened, an original operation line and a track bed are demounted; drawing-out, combination and installation of a frontgirder sheet and a back girder sheet can be performed through an operation platform; the front girder sheet and the back girder sheet are arranged on a constructed back buttress and a constructed front buttress respectively; the whole girder sheets can replace the original railway track bed and tracks, form a temporary bridge structure, can erect a railway line so as to dig a lower roadbed, push astructure or construct. The erecting device is novel in style, is simple in structure, is easy to operate, is high in practicability, can shorten the construction period and the railway blocking construction time, is wide in market prospect, and is suitable for large-range promotion and application.