Abstract: The energy consumption characteristics of major equipments in flue gas desulfurization（FGD） system were analyzed,and the mathematical relationship among energy consumption and several parameters including the unit load,the sulfur content of coal,and the desulfurization efficiency was found.On this basis,we proposed optimization operation ways for energy conservation.Finally taking a typical 1 000 MW FGD system as an example,its optimization operation plans were analyzed.Between 40% and 100% boiler maximum continue rate（BMCR） load conditions,neither adding any new equipments,nor having an impact on safe and stable operation of the unit,these optimization operation plans can reduce electricity consumption by 2%~22%.Under most conditions,consumption reduction can reach more than 10%.According to typical load condition estimation,the yearly electric energy can save above 5 052 MW h and electricity consumption is decreased by 10.6% when compared with the initial scheme on the basis of the guarantee of the desulfurization effect.