The extraction of hydrogen peroxide by means of deionized water from anthraquinone working solution via anthraquinone process was carried out in a gas-agitated sieve plate extraction column. The effects of the superficial velocity of air, dispersed phase and continuous phase on the overall plate extraction efficiency have been investigated. The corrections for the prediction of the overall plate extraction efficiency were presented. The correction proposed to predict the overall plate extraction efficiency in the air, water, anthraquinone working solution three-phase system agreed satisfactory with experimental data with a maximum absolute deviation of 5.6 %. A new design method for gas-liquid-liquid three-phase extractors is developed based on the multistage countercurrent extraction model. The calculated data by the model agreed well with experimental data and the average relative deviation was less than 10 %. Moreover, the model was used to predict a gas-agitated sieve plate extraction column for industrial production of hydrogen peroxide. The results show that the plate numbers of gas-agitated sieve plate extraction column are 30-40 % less than that of liquid-liquid sieve plate column.