In order to solve the problems of overriding trip, fault crossing and expanding blackout area in 6/10 kV power supply system, in view of the common multistage series power supply in some industrial and mining enterprises, the coal smart power supply system is constructed based on the smart substation. The coal smart power supply systems share information by the GOOSE, and on this basis, fault identification and isolation system is constructed to comprehensively process and estimate and achieve the state identification and visualization of a variety of through-fault and abnormal operating state. Fault matrix algorithm is built to realize the identification of fault section and decision algorithm is further optimized. The relevant GOOSE key technology is discussed. It can provide theoretical basis analysis for the advanced applications of smart substation in industrial and mining enterprises, which has great practical value.