Abstract:The polysaccharides were extracted from the Hypsizygus marmoreus waste substrate by microwave-assisted extraction，and the extraction process was optimized by controlling the extraction time， microwave power and liquid-to-solid ratio. On the basis of single factor test and obtained by the response surface method， we got obtained by the response surface method： the extraction time was 10 min， the microwave power was 420 W， and ratio of liquid to material was 31∶1（mL/g）. Under these conditions， the extraction efficiency of polysaccharide from waste substrate was the best， and the extraction rate was 2.01 %.