The invention provides a dual-system synchronous security computer platform, which is composed of a main control layer and an execution layer, wherein the main control layer is composed of a main control module, and is divided into main and standby systems, that is, is divided into a main control module A and a main control module B; the execution layer consists of a certain number of expandable execution modules, each of which is further divided into a security-related module and a non-security-related module, and the design of power supply isolation and bus isolation is carried out for the security function modules and the non-security function modules; the security computer platform adopts a double 2-vote-2 security redundancy architecture; all modules of the platform are connected by means of internal redundant CANFD buses; and the main control modules of the main and standby systems in the main control layer adopt Ethernet buses to implement main and standby machine synchronization and data interaction communication of the main and standby systems. The dual-system synchronous security computer platform has the technical advantages that the expansibility is excellent, the independent and redundant bus architecture is adopted between the main and standby systems, the security modules and non-security modules adopt the power supply isolation and bus isolation security design,and the reliability and security are higher.