Abstract: The security access scheme of personal health files using blockchain as a data storage platform is a hot research topic. The data on the blockchain cannot be tampered with, effectively ensuring the security of the data. Therefore, based on the characteristics of blockchain, a secure access scheme for personal health files based on blockchain is proposed. In this scheme, the patient granted the proxy signer the access rights to his personal health file in advance, and the authorization information was stored in the private chain of the authorized institution to which the proxy signer belonged, so as to ensure that doctors could still have normal access to their personal health files under the circumstances beyond the control of patients. The scheme satisfied non-repudiation and unforgeability, and had higher security and lower computational complexity.