It has a great practical value to study what kind of patent licensing can put university patent into practice. Applying the theory of principal-agent, a model of implement of university patents is built up based on the moral risk of inventors and licensees from the perspective of patent licensing. By finding the solution for the equilibrium result, it is indicated that the problem of moral risk leads to inefficiency of patents implement. Through analysis of the characteristics of optimal licensing contract, some practical suggestions on how to constraint moral risk are brought forward for promoting the implement of patent.