Abstract: Power supply systems for urban rail transit generally adopt centralized power supply mode, each line deploys multiple main substations as its power source and these main substations assist each other to guarantee the power supply reliability. However, being constantly influenced by construction process of civil engineering or main substations, urban rail transit lines sometimes have to build temporary power sources due to the insufficient power sources for trial operation. Meanwhile, as line networks stepping into the stage of networking operation, adjusting the power supply modes in a flexible way is needed. Considering the feature that medium-voltage network in urban rail transit power supply system usually adopts ring network connection mode, combined with practical engineering cases, the necessity and feasibility of deploying interconnection ring network among lines at the interchange stations are analyzed.Suggestions for implementing interconnection ring network among lines in different construction time sequences are proposed.The application prospect of interconnection ring network based on line network power dispatching platform is also analyzed.To ensure lines to be launched on time either under construction or in future plans, setting interconnection ring network at interchange station provides an idea of establishing temporary power source or back-up power source, meanwhile, providing a variety of power supply architectures and power supply mode options for the networking operation of the line network.