In the medical development of our country, the role of medical consortium is more and more significant. The mode of hierarchical medical treatment and two-way referral of medical consortium makes it convenient for the masses to seek medical treatment, which gives full play to the leading role of tertiary hospitals and promotes the construction and development of modern medical treatment. In the construction of medical consortium, data security should be guaranteed when data is Shared between hospitals, and clear protocol standards should be established. Traditional medical consortium architecture cannot solve these problems. This paper adopts the alliance chain technology in the block chain, and puts forward a new technical idea and system framework for the construction of modern medical consortium based on the decentralization and security features of the block chain, so as to make the medical consortium better adapt to the development of the medical field.