Dynamic real-name authentication refers to a system based on digital signature and authenticated by personal real information. Real-name authentication is an important part of network security technology. This paper analyzes the principles of response authentication mechanism and digital signature technology, and puts forward an optimized dynamic identity authentication system based on digital signature in view of the defects of the existing dynamic identity authentication system. The system reverses the challenge direction of the response authentication mechanism, and the challenge initiation action is realized by the client. The analysis results show that the system can reduce the communication times between the two parties in the authentication process, resist network replay attacks, violent attacks and prevent network eavesdropping, and support two-way identity authentication.