Abstract: Using the environmentally friendly reaction solvent (acetic acid) to the hydrolysis the soapstock in the high-pressure magnetic agitator, to study the solid-liquid ratio, reaction temperature, reaction time, reaction pressure on the rate of hydrolysis of soapstock.Using the method of univariate and response surface optimization to finalize the anti-optimal conditions were:liquid ratio was 1:2.2, the reaction temperature was 290℃, the reaction time was 45min, the reaction pressure was 14MPa, the fatty acids extraction rate in the optimal conditions was 96.5%.Compared with the traditional methods, the method of sub-critical acetic acid hydrolysis could significantly shorten the extraction time without chemical catalyst and acid, ensure the purity of the product, so that was green.