Abstract: Aviation safety involves a wide range of fields, and the knowledge needed to be expressed is more complex. The construction of security management knowledge base based on ontology is divided into the following three steps: Firstly, the hierarchical relationship, attributes and attribute constraints among the three categories of civil aviation accidents, causes and management measures were be defined. The setting of categories and attributes established the relationship among various knowledge blocks of civil aviation safety. Secondly, in order to improve the expression ability of knowledge base, the ontology of security management domain built by Protégé5.2.0 was used to realize knowledge integration, knowledge acquisition and knowledge sharing among different users. Finally, in the ontology knowledge base, the improved seven step method was used to create aviation safety accident cases from 2010 to 2018. Knowledge base could be used to quickly identify the causes of safety accidents. Effective measures could be taken to reduce the risk of accidents, and the safety management level of civil aviation industry should be further improved.