With the development of Internet technology, Internet has entered each field of society. At the same time, the popularity of network has led to the some illegal activities which are implemented by using network vulnerabilities. In addition, the risk of valuable information’s being abused has drastically increased. Thus, it is one of the pressing tasks at issue that we should solve the security of Internet information and provide a reliable Internet information security policy. First of all, this article analyzes the application system framework of digital certificate and its safety features, and then combined with the certificate of data frame and the body's immune model, this paper builds the multidimensional network information security platform framework on the basis of digital certificates. By doing this, the client safety and the master-slave structure security have been effectively solved. Next, this paper makes a case analysis. Furthermore, digital certificate is innovatively applied to data nodes of the network information data integrity protection. According to the markov model, this paper constructs the model of data integrity based on digital certificate and then this paper makes test and simulation on the accuracy of the model through the VB. NET programming. The result shows that the model has obvious effect on data integrity protection. To some extent, it provides theory and practice support for the research in this field.