Under the background of simulation engineering in Guiyang Power Training Center substation, in order to shorten the substation simulation development process and narrow the gap between simulation products developed by different levels of technical staff, the relay library is designed. Based on the full graphical simulation modeling support platform, through studying the characteristics of all kinds of main equipment protection device of the substation, and based on the secondary circuit diagram of various types of computer protection used in the research and development of the substation simulation, this paper proposes to establish relay library with standardized naming and modular function design. Each set of protection in the library can be configured for different substations, and can facilitate the rapid relay modeling and the automatic tuning of protection setting value.