With fresh pyrus nivalis as raw materials, studied the effects of ultrasonic power, temperature, solid-liquid ratio, and time on the extraction efficiency of polysaccharose using sonication-assisted extraction method. On the basis of single factor experiment, the orthogonal experiments were designed to optimize the extraction process. Moreover, polysaccharide was applied to cigarettes. The results of orthogonal experiments showed that : The optimal conditions were solid-liquid ratio 1:4 (g/mL), temperature 50 ℃, time 50 min, ultrasonic power 160 W; Under this condition, the extraction yield of polysaccharide was 3.18%. The results of experiment with polysaccharide as cigarettes flavor indicated that polysaccharide extracted from pyrus nivalis can cover the offensive taste, soften smoke gas, reduce the stimulus, enrich the flavor of smoke, produce saliva and slake thirst.