Abstract: Aimed at the problems of traditional medical data privacy transmission and sharing vulnerable to malicious attacks and the lack of unified standards, which leads to difficulties in sharing and data isolation, blockchain technology is combined with the medical system to achieve secure data sharing through distributed ciphertext storage, through the legitimacy authentication of nodes and the hybrid signature algorithm to ensure the security and integrity of patient data privacy. Through experimental analysis, the scheme can significantly improve the utilization rate of nodes and the efficiency of data sharing, reduce the delay, and help realize the security protection of medical data privacy.