Abstract: Pancreatin was extracted from yak pancreas,enzyme activity and yield was used as the measurement index.On the basis of single factor experiment,the orthogonal test was used to determine the optimization of technological parameters of yak pancreatin preparation,at the same time,the effects of hydrolyzing casein was investigated using pancreatin to prepare lactoalbumin hydrolysate. The results showed that the optimum technological condition for preparation of yak pancreatin was as follows: yak pancreas ∶ 25% ethanol( extracting agent) = 1 ∶ 1,extraction and activation time was 5 h,p H = 6.8,75% ethanol precipitated for 8 h. Under these conditions,enzyme activity of trypsin,amylase and lipase were 1867,16298 U / g and 5683 U / g respectively,the yield reached 9.7%.Then the pancreatin add to casein with ratio of 1∶5 to prepare lactoalbumin hydrolysate under40 ℃,p H7.5 for 4 h. Consistant with Hyclone,there were 19 kinds of amino acids in hydrolysis product,but the contants of total amino acids were higher than Hyclone: the percentage was 36.111% and 27.725% respectively.In conclusion,this technique is simple,time saving,feasibility to be industrialized,and will be a good application prospect in the field of protein hydrolysate.