Research on design and implementation of data interfaces in the desktop testing platform for a certain satellite was introduced in this paper.Firstly,to satisfy the engineering requirements,general structure of the platform was designed with the real-time simulator and the on-board computer as its core components,and the interfaces among various components in the platform was described.Then,topic focused on researching problems including constitution of the real-time simulator,programming on interfaces using xPC Target,sample time of the interfaces,encoding double precision floating point number for transmission through interfaces,and design of CAN bus protocol on the application layer.Finally,by analyzing results of the testing experiment,effectiveness and practicality of the data interfaces solution were proved.