Abstract: The reaction conditions were optimized by vacuum-coupled ultrasonic extraction of the saponins of the saponin from Aralia elata,and the anti-oxidation and antibacterial activities of the saponins of the saponins were studied by vacuum coupled ultrasonic extraction,atmospheric pressure ultrasonic assisted and solvent extraction techniques. influences. Results showed that,the optimum conditions were 80% ethanol,material-solvent ratio 1:25 g/mL,ultrasonic temperature 58 ℃,duration 50 min,ultrasonic power 270 W,vacuum level 0.08 MPa,yield of Aralia elata saponin was 4.18%. This technology could significantly increased the yield and shorted the duration compared with the other two technologies. The antioxidant test showed that the antioxidant activity of Aralia elata saponin extracted by ultrasonic coupled vacuum technology was closed to that of Vitamin C,and significantly higher than those of saponins extracted by atmospheric pressure ultrasonic extraction and solvent extraction. The IC₅₀ values of ultrasonic coupled vacuum technology extracted Aralia elata saponin were 0.344 mg/mL to DPPH radical,1.367 mg/mL to hydroxyl radical,and the maximum total reduction capacity OD value was 0.893.Antibacterial activity test showed that Aralia elata saponin had inhibitory effects on Escherichia coli and Staphylococcus aureus,but no inhibitory effect on Bacillus subtilis. The ultrasonic coupled vacuum technology extracted Aralia elata saponin showed strongest inhibitory effects,while solvent extracted one showed the weakest effect. The minimum inhibitory concentrations of ultrasonic coupled vacuum technology extracted Aralia elata saponin were 2.5 mg/mL to Escherichia coli and 10 mg/mL to Staphylococcus aureus.