A digital certificate based information security realization method and system are provided. The method includes: separately issuing a digital certificate for a cloud management host, a physical cloud computing host and a virtual cloud computing machine; and carrying out a compliance authentication according to a corresponding digital certificate when the cloud management host, the physical cloud computing host and the virtual cloud computing machine start up or are in the running process. By using a digital certificate trust chain technology for reference and combining with a cloud management system, the digital certificate based information security realization method and system provided in embodiments of the present disclosure realize trusted systems of the cloud management system, the physical host and the virtual machine; beside, by putting emphasis on the security protection of the host platform of a system itself, the security of a virtual cloud platform is improved.