The Pleurotus ostreatus were used as the raw material for extracting polysaccharide by means of smashing extractor, ultrasonic extraction, ultrasonicassisted complex enzyme extraction. The results indicate the optimal extraction conditions of the smashing extractor were extraction temperature 90 ℃, extraction rate 11 350 r/min, extraction time 20 min, extraction 3 times, and the yield of polysaccharide extracted was 11.20%. The optimal extraction conditions of ultrasonic extraction were extraction temperature 60 ℃, extraction time 60 min, ultrasonic power 450 W, extraction 3 times, and the yield of polysaccharide extracted was 9.75%. The optimal extraction conditions of ultrasonicassisted complex enzyme extraction were extraction temperature 30 ℃, extraction time 60 min, ultrasonic power 350 W, extraction pH 5, the yield of polysaccharide extracted was 1205%. In comprehensive consideration of the yield of polysaccharide extracted, saving energy, simple operation, the smashing extractor was considered as an ideal method.