According to the characteristics of spatial data in geographic information system for power, compared to the traditional spatial data models, introducing the relationship to the construction of the object model, the paper proposes a new object-relational model, discussses the cognitive process and structure of spatial data model of power and illustrates the construction of the model and the methods to organize, manage, and query spatial data based on the model. and proves the model is feasible, it can represent the topology of power network better, simplify the management operation, and improve the stability and sharing of spatial data.