The present invention proposes a digital certificate generation, identity authentication method, quantum CA authentication center and system, each CA authentication center is used to provide message authenticity authentication function, that is, quantum digital signature service based on credible identity authentication, the CA authentication center It includes a registration authentication unit, a basic function unit, a quantum security unit and an interface unit connected in sequence. When a signature is initiated between two users, the CA certification center and the communication parties jointly constitute a message authenticity verification system. First, the signer requests the CA certification center for "one identity at a time" authentication, and then prepares a key, generates a signature, and verifies the signature These several processes complete the quantum security verification of the authenticity of the sent message and complete the quantum digital signature. The CA certification center of the present invention needs to issue a trusted identity certificate to each user, but the certificate does not need to be bound with the key for verifying the signature, so the certificate management of the quantum-safe CA center is more convenient.