Using the scraps such as the stalks of bisporus mushrooms and irregular mushrooms produced in the factory as raw materials,the protein of Agaricus bisporus is extracted by the alkaline solution and acid precipitation method,after ultrasonic treatment,trypsin,alkaline protease and composite protease were selected to hydrolyze the protein.By measuring the degree of protein hydrolysis and ACE inhibition rate,the best kind of protease was determined.In order to obtain the active peptide with higher ACE inhibition rate,the enzymatic hydrolysis conditions were optimized by using response surface methodology(RSM).The results showed that the ACE inhibition rate of A.bisporus protein hydrolyzed by alkaline protease was the highest.The optimal process parameters were as follows:the addition amount of alkaline protease was 6.25 mg/100 mL,the hydrolysis temperature was 40.47 ℃,the hydrolysis time was 92.97 min,and the hydrolysis pH was 8.04,the ACE inhibition rate can reach 43.75%.A verification test was performed under the condition,and the ACE inhibition rate of the hydrolyzed solution was 43.4%,which was close to the predicted value.After ultrafiltration and vacuum freeze-drying,the peptide sample with potential ACE inhibitory activity was prepared,and the yield was 24.36 mg/g.The industrial production prospect was good,which could provide a new way for the high value utilization of the industrial scraps of A.bisporus.