Abstract: Electronic medical record (EMR) is the private data of patients for relevant medical diagnosis, but the relevant insurance claims will access these private data in clear text, which is easy to cause the disclosure of private data and the risk of data security. In order to solve the above problems, it is proposed that the centralized management and storage of electronic medical records can be realized by using blockchain and smart contract. The patient's electronic medical records were stored in the InterPlanetary file system (IPFS) and associated with the patient's data through smart contract. When a patient saw a doctor in the hospital, a claim settlement contract was directly generated. When settling a claim, the insurance company did not need to obtain the explicit information of the patient's electronic medical record. It judged whether the insurance needed to settle a claim through the claim settlement contract, so as to realize the purpose of standardizing the insurance claim settlement and protecting the user's privacy data.