Abstract: To achieve efficient and stable operation of the trough solar collector system, a control system based on NA2000 series PLC is designed against the background of the Taiyuan trough solar collector demonstration project. A local control cabinet is adopted as the field interaction unit, combined with multi-mode control logic and a high-precision sun-tracking algorithm to realize one-dimensional sun tracking of the trough concentrator. Field tests show that the system tracking angle deviation is ≤±0.1°, the heat collection temperature can reach 400℃, and the concentration ratio is 10~100. The system can realize flexible switching among automatic heat collection, energy-saving operation and manual intervention. It adapts to the industrial field environment with sufficient reserved expansion interfaces, which verifies the practicability and reliability of domestic PLC in the field of solar thermal utilization and provides a feasible scheme for engineering applications.