The breach of contract of order - oriented medical students directly impacts the effectiveness of free training policy for oriented medical students. Based on the dual analysis of incomplete contracting theory and economic man theory，the study found that multiple factors，such as the game of limited rationality behind the different value orientations of the state and order - oriented medical students，the increasing tendency of deviation in the process of the tension between policy certainty commitment and uncertainty，the breeding of opportunistic behavior of information asymmetry of oriented medical students in free training，the imbalance between medical education investment and individual interests and other factors，lead to the risk of breach of contract. To avoid the risk of breach of contract for order - oriented medical students，we must recognize the objective existence of the incompleteness of the employment contract and associate all interested parties to concede the space of interests and construct effective governance strategies.