Abstract: Aiming at the problems of insufficient organization, sharing and reuse for knowledge of emergency treatment case of high-speed railway signalling and communication equipment fault (abbreviated as: emergency case of electrical affairs), this paper introduced ontology knowledge into emergency case knowledge management, analyzed the emergency case knowledge representation tuple, constructed the emergency case knowledge meta ontology model, the emergency case knowledge model, as well as emergency case base and rule base. Taking a railway traffic accident as an example, the paper carried out the reasoning and practical application of electrical emergency case knowledge. The results show that the ontology knowledge base of high-speed railway electrical emergency case can carry out knowledge organization and automatic reasoning of knowledge better, and improve the sharing and application efficiency of emergency case knowledge.