The utilization of JM810 NC device has greatly met the requirments of the precise and reliable thyristor units’ steady flow control. The utilization of core unit of the minimum steady flow and design technology of all digital, dual-channel redundant and hot standby steady flow system has ensured the long-term operation. Self-diagnosis and intelligent control and protection process of real-time system, realization of synchronizing signal, abnormal feedbacks of AC-DC, overcurrent of the unit, malfunction of the trigger, dual-channel monitoring, automatic detection and intelligent protection processing have substantially improved the reliability of overall system. Fully functional PLC control system has improved the equipment’s operating safety and the effectiveness of protection and control.