Abstract: For the knowledge ontology related application, combined with the relevant content of knowledge retrieval, the problems of knowledge retrieval is analyzed.The retrieval mechanism for the hoist fault knowledge ontology is constructed;the retrieval processes of ontology-based hoist fault knowledge is given;a detailed analysis of the query constructor, query engine and the results custom modules is focused;the specific structure and realization of each module is given.Finally, combined with hoist fault knowledge ontology, the implementation and application of system show this method help to increase the reusability and generality of the hoist fault knowledge;the system can provide users with comprehensive and accurate domain knowledge and also verify the method is effective and correct proposed in this thesis.