Abstract: The protein from lentinus edodes stalk was subjected to hydrolysis to prepare the antioxidant peptides,providing a theoretical basis for the deep processing of mushroom stem. Firstly,the protease was screened,then the single factor experiment was carried out on the basis of Alkaline protease. Four factors and three levels of response surface analysis were used to study the effects of substrate concentration,enzyme concentration,pH and temperature on the extraction process. DPPH scavenging capacity was used as the response value,the optimal conditions for the enzymatic hydrolysis technique were determined as follows: substrate concentration of 2%,enzyme concentration of 4700 U / g,pH8.3,hydrolysis temperature of 55 ℃,hydrolysis time of 2.5 h. Under these conditions,the DPPH scavenging ratio was 63.2%. Letinous edodes stalk polypeptide had a certain antioxidant activity,providing the basis for the development of letinous edodes stalk products.