Coordinated control system(CCS) of circulating fluidized bed combustion boiler is one of the difficulties in automatic control of CFB boiler.The configuration of each subsystem of CCS is briefly introduced according to the first 300 MW CFB boiler in Sichuan Baima Demonstration Substation
which is imported from ALSTOM of France.The effect of adding external bed on decoupling of the complicated coupling parameter is described as well as the experiences during the commissioning of 300 MW CFB boiler.