This paper proposed a domain ontology construction method based on knowledge graphs. This domain ontology was constructed based on the mature idea of software engineering by using the "HowNet" as the semantic knowledge resources, and knowledge graphs as a semantic representation. It has a clear structure with clear semantic meaning. It can provide effective supports for some applications such as semantic Web and information extraction. This paper introduced the concept of ontology, the standard of design, the process of modeling, and future prospects of ontology portability. This method was proved to be more effective than traditional ontology construction method in uncertain knowledge processing by experimental results.