The utility model relates to an empty core plate case roof beam of active powder concrete of railway. Little, the poor stability of active powder concrete thin wall simple box girder structural stiffness, the quality was difficult when the just whole big cross -section in hole was prefabricated guarantees. The utility model discloses a case roof beam includes the web of both sides between corbel back slab and the roof and the bottom plate of independent prefabricated roof, bottom plate, roof both sides, and roof, corbel back slab, web and bottom plate all adopt active powder concrete material, for empty core plate spare, the bottom plate is cast -in -place for the bottom plate with the department of meeting of web, and the bottom plate is cast -in -place including controlling two departments, roof and corbel back slab and the web yu yichu that meets, the department of meeting is cast -in -place for the roof, cast -in -place about including two departments of roof, roof, corbel back slab, web and bottom plate splice into confined case girder construction through a cast in situ concrete that meets. The utility model discloses disassemble conventional case girder construction into prefabricated plate structure, utilize hollow section's characteristics, measure in unchangeable active powder concrete masonry, increased the rigidity of structure.