Abstract: To address the response latency and operational efficiency bottlenecks caused by manual local operation in smart substation secondary equipment control, this study investigates a PLC-based remote control method for smart substations. By establishing a deterministic communication framework integrated with Time-Sensitive Networking (TSN), the method achieves synchronized transmission and lossless delivery of multi-source control commands. Hardware-independent command mapping and state feedback mechanisms are designed to enable unified abstraction and management of secondary equipment from various sources. A logical virtualization layer is introduced to dynamically reconfigure discrete control functions and implement redundant fault tolerance. Comparative experiments demonstrate that the proposed method significantly improves both response performance and operational efficiency, providing an extensible technical pathway for building a highly reliable, adaptive remote operation system for large-scale substation clusters.