To ensure the effectiveness of energy-saving strategies, this study proposes an energy-saving optimization model for train schedules that considers the traction power supply system. Initially, a power calculation model based on the traction power supply system is established to obtain the power profiles for the full-line operation of inbound and outbound trains. By modeling the train as an equivalent power source, a DC-side power flow calculation model of the traction power supply network is established. Subsequently, a regenerative braking energy calculation model is developed, by analyzing the effective overlapping time of different train sequences. Based on this, a mixed-integer linear programming model is constructed with the objective of maximizing the total utilization of regenerative braking energy in the timetable. The Gurobi solver is used to optimize the energy-saving timetable, using departure and arrive times as variables. A simulation analysis of a real metro line demonstrates that the total energy consumption of the optimized timetable is reduced by 20.34%, and the utilization of regenerative braking energy is increased to 54.89%.