Abstract: In this work，various experimental parameters were optimized including the absorption liquid pH value, flue gas flow rate, concentration of sulfur dioxide, liquid-gas ratio, and Mg2+/S etc. The effect of the operating parameters on the desulphurization efficiency was analyzed. According to the results of single factors test, orthogonal test scheme was designed. The results provided the optimum control parameters and operation mode to improve the efficiency and the availability of FGD. The optimal proposal was 5.0 pH value of the absorption liquid, 325 000 m3/h of the flue gas flow rates, 1100 mg/m3 of the concentration of sulfur dioxide, 4.7 of the liquid-gas ratio and 1.4 of the Mg2+/S was. Under the  optimum condition, the desulfurization efficiency could reach 95.8%.