International Journal of Information Studies Wang Hong , Fan Hongjie, Li Jian, Wang Jing 7 3 2015 https://www.dline.info/ijis/fulltext/v17n3/ijisv7n3_2.pdf In order to solve the problem of semantic query based on civil aviation emergency domain ontology (CAEDO), a method of semantic query expansion is proposed considering the taxonomic and non-taxonomic relationships in the domain ontology comprehensively. In this method, the calculation of semantic similarity is improved based on the distance and semantic sharing degree for the taxonomic relationships, and the calculation of semantic relevancy on the basis of object properties is proposed for the non-taxonomic relationships. Furthermore, the feasibility of the method is verified by some experiments. The experimental results show that compared with the traditional method, the precision and recall are improved. Moreover, a methodological support is provided for semantic retrieval and generation of rescue plan based on CAEDO.