It is inevitable that the construction of urban and rural medical security system is the law of economic and social development， but there are still more constraints in this social system engineering. Deep analysis and research were carried out from six aspects in this paper such as the constraints of tradi-tional thought and economy， obstruction of the existing household registration system， constraints of the existing land system， legal obstacles and institutional barriers； and ways to solve the problems were trying to be found in order to methods for the construction of the urban and rural medical security system in our country.