Research conclusions：(1)The selection of network system for urban rail transit should obtain the intention of the 1ine network planning,and integrate with the features of the project.It is also beneficial for the operation and the administration and resources sharing.(2)In order to share resources,it can fulfill the organization of the operation of crossover line trains and the reduction of passengers transference in requires.In general,the same system should be applied in the whole city railway network in one city.(3)The amount of the investment of engineering should not be the determined factors for the system selection.(4)Based on the research,it is analyzed that AC(alternating current)power system best fits the rail transit in such city region network.(5)This article not only provides certain theoretical basis for urban railway related research,but also makes a reference for other cities.