Abstract: This study focuses on enhancing the reliability of power supply for control circuits in low-voltage power supply systems. Through comprehensive analysis and research encompassing power supply connection modes, system wiring, and power supply redundancy, a complete optimized design scheme is proposed. In engineering practice, taking the flue gas ultra-low emission renovation project of gas-fired boilers in a steel plant as a case study, the application of this optimized design scheme has significantly reduced the failure rate of control power supply and improved the operational stability of the low-voltage power supply system. Consequently, it ensures the stable operation of process production equipment, demonstrating significant engineering application value and providing practical new ideas and methodologies for the sustained enhancement of power supply reliability in control circuits of low-voltage power supply systems.