在基于实例的产品设计中,产品数据模型的建立和产品数据结构的设计对于产品相似实例的检索与提取有着至关重要的影响.该文分析了递阶结构表达方式的不足,利用扩展的实体关联(EER)表达方式建立了产品的数据模型,并以油泵产品为例建立了产品数据模型的展开结构.在EER模型向关系模型的转化中,提出了4条转化规则,同时以油泵产品为例,设计了产品主关联数据库和子实例库,实现了实例按属性空间和功能空间进行检索的功能. In instance-based product design, the establishment of product data model and the design of product data structure are crucial for the retrieval and extraction of similar instances of product.This paper analyzes the shortcomings of hierarchical structure expression, (EER), a data model of the product was established, and the product data model was developed by taking the pump product as an example.When the EER model was transformed into a relational model, four conversion rules were proposed, For example, we designed the product main relation database and sub-instance library, and realized the function of retrieving the instance by attribute space and function space.