The paper probes into the development of medical insurance informatization in China from three perspectives, namely the structural development history of the medical insurance information system, its functions and the utilization of medical insurance data. Regarding deficiencies in the process of informatization, it proposes that we should utilize cloud technology to develop the medical insurance cloud system, make it standard gradually and establish a "Three-in-one" system, guarantee its powerful functions, and apply the big data technology so as to facilitate the utilization of medical insurance data and provide a reference for the informatization development of medical insurance in China.