To optimize the hydrolysis conditions of squid skin by papain, the effects of the papain dosage, hydrolysis time and hydrolysis temperature on the degree of hydrolysis (DH) were studied by single factor experiment. The results showed that all the three factors exerted certain influences on the DH. Then the Box-Benhnken response surface methods were performed, taking the dosage of protease, contact time and hydrolysis temperature as independent variables to the DH for its optimal response value. Through the response surface analysis, a quadratic polynomial mathematical model was established to optimize the hydrolysis conditions, and the optimal hydrolysis conditions were obtained as follows: dosage of protease should be 4560 U/g, hydrolysis time 3.2 h and hydrolysis temperature 50℃. Under these optimal conditions, the DH could reach up to 15.53%, which was basically consist with the predicted value by the model. The research shows that, the mathematical model obtained through response surface method can rather precisely predict the hydrolysis effect of papain for squid skin, and the research results provide reference for improving the utilization rate of by-products from squid processing.