In order to set up the optimization of water extraction technique of polysaccharides from truffles,the yield of crude polysaccharides was chosen as the index,based on the principle of Box-Benhnken Center combination experimental design,the optimization of extraction technique of polysaccharides was carried out by three factors on three levels.The results showed the highest extraction ratio(10.8%) was obtained at 94.68℃,extraction 3.71h,and Water-solid ratio of 58.66.Evaluation of antioxidant activity is measured by DPPH radical scavenging activity,Hydroxyl radical scavenging activity and Reducing power.The results indicate that crude polysaccharide of truffles has a good antioxidant activity.