Abstract: In order to meet the general technical requirements of urban rail transit for trackside safety computer platform, this article introduced the overall architecture, safety principle, design and implementation of a safety computer platform. The platform comprehensively adopted the safety self-discipline technology based on safety Ethernet bus, complete on-line self-test and dual channel fault management technology, and dual system switching technology based on reliable communication. It has been independently developed and has passed the SIL4 level safety certification, and has been successfully applied to many projects such as Communication Based Train Control (CBTC) system, train independent operation system, tram signal system. The actual operation shows that the platform fully meets the technical requirements of safety, reliability and versatility of various signal systems.