Abstract: In order to study the preparation and stability of antioxidant peptides of Pleurotus eryngii stalk the Pleurotus eryngii stalk as raw material were prepared by enzymatic hydrolysis. The enzymolysis time,the ratio of material to liquid and the amount of alkaline protease added enzyme were optimized by the response surface methodology. Results showed that the best results were obtained by screening the alkaline protease. The enzymatic hydrolysis time was 1.59 h,the liquid-to-material ratio(mL/g)was 16.06:1 mL/g,the alkaline protease plus enzyme amount was 5846 U/g,and the DPPH free radical scavenging rate was 55.52%±0.89%.Antioxidant peptides at a temperature of 20~100℃,pH2~12,metal ions(K⁺,Ca²⁺,Zn²⁺,Mg²⁺,Cu²⁺),food materials(5.0% NaCl,glucose,starch,sucrose,lactose)acted different antioxidant activity. The process could well prepare the antioxidant peptides of Pleurotus eryngii stalk. At the same time,it should avoid contact with high temperature,strong acid and alkali environment and metal ions during storage,which would provide a theory for further development and utilization of Pleurotus eryngii.