Abstract: The mung bean protein prepared by alkali extraction and acid precipitation was used to optimize the preparation process mung bean protein hydrolysate by Box-Behnken response surface methodology. Based on the results of the single factor experiments,hydrolysis time,substrate concentration,enzyme dosage and hydrolysis temperature were selected as influence factor to investigate the binding ability of mung bean protein hydrolysate with sodium deoxycholate by the response surface methodology. Ultrafiltration was carried out on mung bean protein hydrolysate prepared under the optimal conditions. Then the hydrolysate with better hypolipidemic effect was obtained through the purification by Sephacryl S-100 High Resolution gel chromatography column. The results showed that the highest combination effect of the hydrolysate and sodium deoxycholate was obtained under these conditions:Hydrolysis time was 146 min,substrate concentration was 3.1 g/100 mL,enzyme dosage was 9861 U/g,and hydrolysis temperature was 52.1 ℃. And its combination ratio was 60.46%,which was close to the predicted value of 61.86%,with little error. The retentate of the hydrolysate was much more active after ultrafiltering the mung bean protein lipid-lowering hydrolysate,which was prepared in the way mentioned above.