The purchase of social audit services by public hospitals plays an important role in facilitating the high-quality develop- ment of public hospitals. The key point is to make up for the problems of insufficient internal audit resources and poor audit indepen- dence and objectivity of public hospitals. It mainly elaborates the motivation, risk factors and implementation path of public hospitals’ purchase of social audit services, and carries out strategic research from the aspects of whole-process management, system norms, ser- vice scope and agency contract management, in order to improve the efficiency and effect of public hospitals' purchase of social audit services.