Herein, the enzymatic hydrolysis polypeptide solution with antioxidant activity was prepared by enzymatic hydrolysis with alkaline protease using sheep bone powder as raw material. Taking hydrolysis degree as index, response surface optimization was carried out on the basis of single factor tests of enzymolysis time, enzymolysis temperature, enzyme dosage and enzymolysis pH. Taking sheep bone meal solution which has not been hydrolyzed by alkaline protease as the control group, the antioxidant capacity of the hydrolysate was determined. The results showed that the highest degree of hydrolysis of alkaline protease was (28.36±0.02)% when the enzymolysis time was 5 h, the enzymolysis temperature was 45 ℃, the enzyme dosage was 8 200 U/g, and the enzymolysis pH value was 10. The antioxidant capacity of the enzymolysis solution and the control group both increased with the increase of solution concentration. When the concentration of the solution reached 2.5 mg/mL, the scavenging rate and reducing power of 1,1- diphenyl -2- trinitrophenylhydrazine (DPPH), hydroxyl radical (·OH), superoxide anion radical (O 2·) of sheep bone enzymatic hydrolysate reached the maximum values, which were (65.42±0.11)%, (82.30±0.27)%, (79.83±0.22)%, 0.484±0.007 respectively, significantly higher than those of the control group (P＜0.05). Therefore, the enzymolysis polypeptide liquid obtained by hydrolyzing sheep bone meal with alkaline protease has antioxidant activity in vitro.