For the safety of cross-regional medical collaborative services, it is crucial to identify the identities of the exchange parties. This study combines the Diffie-Hellman (DH) algorithm with the SM9 algorithm published by the State Cryptography Administration of China, uses the common key negotiated by the DH algorithm as a verification factor, and integrates digital signatures to achieve encrypted transmission and bidirectional verification of users. Taking the identity verification of users in the access of electronic medical records between hospitals as a case, this study analyzes the of both communicating parties in cross-regional information sharing and verifies the feasibility and correctness of the scheme through experiments, demonstrating that the scheme has practical application value.