Research conclusions：Research of large hub of rail transit is a process that involves many fields，many control factors， engineering complex，also is a macro to micro process．For large rail transport hub should increase research investment in the early planning．to determine the feasibility of its function and its implementation as soon as possible，the later location adjustment is likely to cause the corresponding transformation project，increase the project implementation difficulty and investment，and make the defect on function of use．At the same time，line layout of large hub inner orbit traffic are complex．the spatial relationship between the hub and line and before and after the interval should be dealed with for meeting the needs of the passengers at maximum limit，analysis and study for a variety of possible layout should be carried out，strive to be comprehensive，in order to get the most reasonable layout scheme．