The objective of this work was to study the sodium alkali(Na2S03) FGD process in a pilot-scale column packed column of diameter 0.4m. Main operating conditions affecting SO2 removal efficiency were investigated experimentally. These conditions include pH value of the absorption solution, liquid-gas ratio, superficial gas velocity, inlet SO2 concentration, temperature of absorption solution and initial Na2SO3 molar concentration. The relation between the ratio of desulfurization and every parameter was investigated. And the suitable operational conditions of SO2 absorption in lab are recommended. The experimental results show that SO2 removal efficiency may be over 80% under the following conditions: pH=6-7,L/G=1-2L/m3, gas superficial velocity is 1-1.5m/s, absorption solution temperature is under 50°C,initial [Na2SO3]≈0.3-0.5mol/L,and SO2 initial concentration is 4300 mg/m3. The experimental data can provide the necessary basic data for the design and operation of the practical desulfurization equipments.