Focusing on the security issues of medical archive information, a privacy protection technology for archive information that integrates blockchain, interstellar file system, and encryption algorithms is proposed. Among them, the research focuses on building an archive information sharing platform based on sharded blockchain, introducing reputation consensus algorithm to adjust computational pressure, and strengthening storage security and sharing stability. At the same time, research has proposed an encryption technique that integrates multiple prime asymmetric encryption algorithms to enhance data privacy protection through multi link encryption and decryption. In terms of data privacy protection, research proposes the integration of multiple encryption technologies. In performance testing, the average gas consumption of this technology in blockchain is only 1.12, far lower than other technologies, and the resource cost advantage is obvious. In the encryption time test, when the number of encryption attributes exceeds 45, the traditional encryption technology significantly increases the encryption time. However, the research technology is similar to reference, and when the number of attributes is between 5 and 15, there is a 7.25% improvement in encryption performance compared to reference. In addition, in government recorded scenarios, the interception rate reached 99.4% under high load (1500 attacks), with 1491 intercepted attacks, outperforming other technologies. In addition, in the delay and throughput testing of the encryption process, the maximum delay of the research technology was only 352 ms when the encryption attributes were 68, and the maximum throughput was 3584 TX/s, both of which were superior to similar technologies. The technology proposed by the research has excellent performance in the privacy management of medical institution archive information. The research content will provide technical support for the protection and management of archive information privacy in the medical field.