China’s multi-level medical security system has made a great contribution to improve the national health and promote the transformation and development of economy and society，but there are still many problems. Based on analysis of these problems and it’s roots，this paper argues that follow the principle of “mandatory insurance，insured based on location”，rebuild the basic medical insurance system，and gradually realize the integration of the basic medical insurance. Take “regime integration，concept transformation” and other measures to improve medical assistance system，safeguard the bottom line. From “financing mechanism”，“level of co-ordination” and other aspects to enhance catastrophic medical insurance，improve the level of security.