Abstract: This study addresses the issues of insufficient time synchronization accuracy, weak redundancy, and lack of operation and maintenance support during the intelligent transformation of conventional substations in China Southern Power Grid. A multi-source redundant time synchronization technology solution based on "dual-source hot standby + hierarchical timing" is proposed and implemented. This solution prioritizes the third-generation Beidou satellite signal as the primary reference and simultaneously introduces ground optical fiber links as redundant references. Master clocks and extended clocks are deployed hierarchically in the main control room, high-voltage room, and the entire station′s terminals are uniformly timed through 1PPS pulses and IRIG-B codes. Engineering verification results show that this solution can improve the timing accuracy to ±0.4 μs, significantly enhancing the system′s anti-interference and self-diagnostic capabilities, and effectively supporting the safe and stable operation of intelligent recording devices, protection devices, and telecontrol systems.