The invention discloses a protection apparatus modeling method applicable to a protection information system (hereinafter referred to as information protection) application analysis function, comprising the following steps: standardizing an IEC 61850 model in an instation protection apparatus, and generating an instation SCD model file; and expanding protection function classes in a main station CIM model by referring to definition of an instation protection model. The classes are kept accordant with protection logic node classes of the IEC 61850, so that mapping can be performed simply without loss to realize seamless conversion from the instation SCD model to the main station CIM model; in addition, the protection apparatus modeling method is high in universality and the protection professionals are easy to understand; the instation standard SCD model is imported through a software tool and to automatically generate the CIM model needed by the main station according to expanding rules, so that the protection apparatus modeling method is high in usability; the protection information system main station and the protection information system sub station are in communication through the IEC 61850 protocol; the CIM model generated in the station is obtained by the file service; and the data subscription and data publishing are realized through the dynamic data set service and report service of the IEC 61850 protocol.