Large-scale particle accelerators have immense energy consumption, which necessitates innovative approaches to improve power efficiency. In this context, the energy recovery control of RF power sources is critical. Driven by the megawatt-level energy recovery demand of RF power sources, this paper focuses on bidirectional energy control. We propose a high-voltage power supply system based on a cascaded Pulse Step Modulation (PSM) architecture. Simulation experiments preliminarily validate that the proposed system not only meets the klystron load energy recovery requirements but also adapts to various energy recovery applications, laying a theoretical and practical foundation for green accelerator engineering. The proposed system integrates 50% unidirectional uncontrolled rectifier modules with 50% bidirectional switchable modules to seamlessly adapt to operational modes including full rectification, hybrid rectification/inversion, and localized intelligent inversion. Detailed mathematical modeling and closed-loop transfer functions confirm critical performance metrics: voltage output ripple below 1% and dynamic response time under 1.5 ms. Advanced control strategies such as soft-start logic and inter-layer error tracking minimize inrush currents and achieve steady-state accuracy within 0.15%. Simulation results further demonstrate a single-cycle energy recovery efficiency of 96.3% and rapid fault-tolerant recovery with voltage overshoots below 0.7%. Overall, this research addresses the efficiency bottlenecks of current RF power sources and paves the way for sustainable accelerator technologies.