With the continuous improvement of the intelligence and digitization of the natural gas pipeline network,a more intelligent demand is put forward for the fault diagnosis and operation maintenance of the natural gas pressure regulating valve.Based on model,knowledge and data drive fault diagnosis technology,the development prospect of “multi theory fusion” fault diagnosis technology was analyzed.Based on model-based and data-driven,knowledge-based and data-driven,and multi-theory fusion fault diagnosis technology three aspects, the research on fault diagnosis of pressure regulating valve was reviewed,problems that the heterogeneity of pressure regulating valve fault diagnosis system,knowledge island,poor generalization were summarized.At the same time,ontology technology was introduced,the characteristics and research status of ontology fault diagnosis technology were expounded,the development direction of the pressure regulating valve fault diagnosis technology was discussed.Under the intelligent development trend of natural gas pipeline network,the application prospect of ontology intelligent fault diagnosis technology based on multi-theory fusion was discussed.