The invention discloses a large coal-fired boiler wet-process flue gas desulfurization device control system and belongs to the field of electrical technology and equipment. The technical scheme includes that an industrial control computer, namely a personal computer, used with a color cathode ray tube (CRT) display, a printer and the like, is used as a host computer for setting process running parameters, system regulating parameters, real-time detected running curves and display equipment failure; a programmable logic controller ( PLC) is used as a slave computer for collecting and operating the equipment parameters and signals, regulating outputs and controlling running of the equipment; the PLC is in intercommunication and interconnection directly with the PC through an expansion RS 232/485 communication module; an uninterrupted power supply UPS is configured to guarantee running of the control system in the situation of power interruption accidentally; a transformer and a power supply filter are configured to improve interference resistance capacity of the control system. The large coal-fired boiler wet-process flue gas desulfurization device control system has the advantages of high advancement and efficiency, high pertinence, simple system, low cost, high potency, capability of meeting control requirements, convenience in maintenance and running reliability.