Based on the single factor experiment,microwave power,ultrasonic temperature,liquid to material ratio were selected as independent variables,and the extraction rate of Polygonatum odoratum polysaccharide was selected as response value. The extraction process was studied by Box-Behnken central composite design and response surface analysis. The reducing power,DPPH and OH radicals of the polysaccharide were determined. The prediction model of regression equation was established. When the ethanol concentration was 70% and the ultrasonic time was 8 min,the optimal extraction conditions were determined as follows: the microwave power was 250 W,the ultrasonic temperature was 50℃,and the ratio of liquid to solid was 30∶1. Under this condition,the extraction rate of Polygonatum odoratum polysaccharide was 8.5 g/100 g. When the concentration of the Polygonatum odoratum polysaccharide was 0.85 mg/mL,the scavenging rates of DPPH and OH radicals were 34.58% and 97.65%,respectively. Box-Behnken Center combination design and the method of response surface analysis can be used to analyze in a continuous range,which has the advantages of short experimental period and high precision. The results of antioxidant research showed that Polygonatum odoratum polysaccharide was a natural antioxidant with development potential,and the results can provide reference for the development of the Polygonatum odoratum polysaccharide products.