The authors used ultrasonic microwave digestion and synergistic extraction to extract polysaccharides from Radix rosea, and analyzed the results by response surface methodology. The result is that the regression model has good fitting degree. The primary and secondary terms of the regression equation reach a significant level. The influence of each factor on the response value is not a simple linear relationship. This regression model can be used to determine the optimal condition range of the extraction process. The optimum extraction conditions for the polysaccharides of wild rose were: cellulase addition mass fraction of 1.15% (enzyme activity 40 U/mg), pH value of 5.72, liquid-to-liquid ratio of 12.56:1 (mL/g), and extraction temperature of 81.19 °C. Under this condition, the actual yield of the polysaccharide of the wild rose root is 10.48 mg / g, which is basically consistent with the model prediction result (10.63 mg / g), the optimized process parameters are accurate and reliable, stable and feasible. The results of the assays in this paper indicate that the polysaccharides of Radix Paeoniae Alba have certain antioxidant properties, and their antioxidant activities increase with the increase of mass concentration. The antioxidant activity of the wild rose root polysaccharide is expected to be exploited as a natural antioxidant and functional product.