Abstract: The single extraction rate of glycyrrhizic acid and the separation rate of glycyrrhizic acid and liquorice were used as indexes, the Glycyrrhiza uralensis ultrafiltration liquid with a concentration of 0.2 g/mL was taken as the research object.Based on the single factor experiments, the factorial experiment was employed to investigate the influence on the extracting effect of glycyrrhizic acid in glycyrrhiza ultrafiltration liquid by changing the composition of complexing extractants, to screen out a complexing extractant and method suitable for separation of glycyrrhizic acid.The results showed that the single extraction rate of 15% TRPO+85% sulfonated kerosene for liquiritin of glycyrrhiza ultrafiltration liquid was 99.59%, the separation rate of liquiritin and glycyrrhizic acid was 91.31%.The single extraction rate of 6% TRPO+50% TBP+44% sulfonated kerosene for glycyrrhizic acid was 32.98%±0.04%.The preparation of glycyrrhizic acid by two step complexation extraction was obtained, it was that 15% TRPO+85% sulfonated kerosene was used to extract glycyrrhizin in the ultrafiltration fluid first, and then 6% TRPO+50% TBP+44% sulfonated kerosene as the extractant to extract glycyrrhizic acid from the extracted water phase.The two step complexation extraction method could obtain glycyrrhizic acid and collect by-product liquiritin.