Abstract: In life cycle management practice of the household electrical appliance enterprises,it still has some insufficient that the product design needs manual archiving and it is difficulty for query and cooperative．The ontology theory was introduced into the field of home appliances．The functional semantic extending method for is-a was presented and used to construct a function body based on studying the top-level ontology construction method of home appliances and extension method of ontology semantic．The index knowledge repository model of user demand-oriented was constructed．The home appliance product design knowledge is expressed by using OWL language.The user needs and ontology knowledge index were transformed to realize the sharing of semantic based on the method of ontology mapping and matching．Final,to verify the correct of the index knowledge model,the semantic sharing plat of refrigerator enterprise design knowledge was established.

Key words: Semantic,Share,Product design,Extension,Similarity