Abstract:Research purposes: Take the key project of Wuhan - Xiaogan Intercity Railway focused on the Fuhe river super large bridge as an example,the detailed design and research were made and done on the structural form, load bearing characteristics,overturning stability and engineering quantity of 32 m double – track ballastless track cast - in - situ simply - supported curved beam located in the range of curve radius 500 m. Through the comparison and analysis of the plane and space,the reliability of the analysis method of 32 m simply - supported curved beam is verified,and some conclusions for the design of curved beam are drawn. Research conclusions: (1)The results shows that,all the indexes of 32 m simply - supported curved beam can meet the specification requirements. The structure is safe and reliable. (2) The simply - supported curved beam is not safe to use straight beam model,the curved beam model should be used to calculate and the strength safety factor should be considered slightly to stay rich. (3) The bending - torsion coupling causes the inner side force and outer side force of simply - supported curved beam to be unequal,the outer side compressive stress of box girder bottom slab is smaller and there is no great difference in the stress characteristics between the curved beam and the straight beam. (4) The bearing arrangement does not affect the internal force distribution of simply - supported curved beam,the beamhas a tendency to move to the outside in the transverse direction. (5 ) Simply - supported curved beam web site can be consistent with the adjacent straight beam size,the web size will not increase. (6) The curved beam length is longer and the secondary dead load is larger. The engineering quantity of the beam is also slightly more than the straight beam,but the increment is in the reasonable scope,the project cost is economical. (7) The beam type can be widely used in the same type of intercity railway,the research methods and conclusions can provide reference for other simply - supported curved beam design.