Abstract: To improve the rice bran oil yield,using ultrasonic assisted aqueous enzymatic method and the demulsify the emulsion,the optimum technological conditions were obtained.The effect of the type,proportion,dosage of enzyme and the hydrolysis conditions on the extraction of rice bran oil was investigated.On the basis of single factor,the Box- Benhnken response surface experiment was carried out.The optimum parameters of the extraction process was solid- to- liquid ratio of 1 ∶ 6,hydrolysis temperature of 51 ℃,hydrolysis time of 5 h,the ultrasonic power of 230 W,ultrasonic time of 20 min,hydrolysis dosage of 1.38%( alkaline protease ∶ compound cellulase ∶pectinase = 1∶ 2∶ 1).Under these optimal hydrolysis conditions,the yield efficiency of rice bran oil was up to 90.53%.