Energy feedback systems and energy storage systems are widely used in urban rail DC traction power supply systems. Aiming at the design of a power supply system with ground regenerative braking energy utilization devices, this study first builds power supply calculation models for different ground regenerative braking energy utilization devices. Based on these models, the theory of optimal design and operation of the power supply system is proposed, which takes the comprehensive cost of the system within the lifetime of the regenerative braking energy utilization device as the objective function in the design phase, and the system traction energy consumption as the objective function in the operation phase. To evaluate the energy-saving effect of the power supply system with ground regenerative braking energy utilization devices, two energy-saving effect evaluation indexes are proposed, which measure energy from traction energy consumption and main transformer energy consumption, respectively. An online monitoring and control system based on an energy-saving effect evaluation is proposed. Finally, some ideas for the design of the power supply system that should be adjusted are presented, which provide a reference for the system design.