Abstract: The 150 days old castrated hen breasts in Yunnan Wuding were used as material, the degree of hydrolysis ( DH) was analyzed, based on the results of the single-factor tests, the optimal hydrolysis condition for chicken breast hydrolyzed by papain and neutral protease was obtained through the Box-Behnken methodology.The results showed that the model was highly significant ( p < 0.0001) , and the lack of fit was not significant ( p = 0.1441 > 0.05) , R²= 0.9919, R_adj²= 0.9815. The optimal enzymolysising process was as follows: papain and neutral protease were mixed and added at the same time, papain and neutral protease was 0.27% and 0.13% respectively, temperature 54.3 ℃, p H6.8, after 5 h under the above reaction conditions, the DH reached 36.03% ± 0.31%, agreed with the predicted value 36.26%. Therefore, the model has a good fit result and provides reference for practical application.