Due to the powerful knowledge representation and reasoning ability, the ontology has been widely used in many domains. Nevertheless, the in-depth application of the ontology still faces many deep common semantic mapping problems. The existing ontology modeling methods only propose some simple guiding principles and basic steps, so that knowledge engineers still have no way to start. When constructing the domain semantic knowledge base based on the domain expert knowledge, the three types of common semantic mapping problems in the domain expert knowledge, such as polysemy, n-ary relationships, and security requirements, are studied in depth from five aspects, the corresponding semantic mapping methods are proposed, and 10 ontology modeling conventions are summarized. Finally, a complete application case is constructed and the five types of semantic mapping methods proposed in this study are evaluated.