In this paper a new design idea has been put forward that combines the oo - layer method with unification method to realize the integration of relation database and object - oriented database . we also present the concepts and structures of power system basic class database and simulation database 本文提出了将oo - layer法与合一法( unification )揉合起来实现关系数据库与面向对象数据库集成的设计思想和电力系统基类数据库、仿真数据库的概念及其体系结构。