Abstract: The process conditions of ultra high-pressure extraction of brewer's yeast were studied.The single-factor experiment and the orthogonal test were adopted to research the influences of solvent, liquid-solid ratio, pressure and time on the extraction yield of yeast oil.The verification of optimal conditions for oil extraction was carried out, and the yeast oil compositions were analyzed by GC-MS method.Results showed that the optimal conditions for yeast oil extraction were as fallows:the ration of solvent to solid was 20:1 (v:m) , using 95% ethanol as the solvent, under the pressure of 400MPa, extracting for 7min, the highest yeast oil yield of 3.7469% obtained to the original yeast biomass.This yield was the 72.11% ratio to the total content detected by the soxhlet extraction.The total fatty acid content was 45.87% in yeast oil.Among which, 34.90% of the unsaturated fatty acid (UFA) with oleic acid, palmitoleic acid, linoleic acid and other polyunsaturated fatty acid composing the vast majority components.The yeast oil also content 46.84% of triglycerides and 7.25% of phospholipids.The ultra high-pressure extract technology could be used in the yeast oil extract process with extremely shorter the time of extract than that of the soxhlet extraction.The yeast oil containing abundant unsaturated fatty acid could be used as drug and functional food.