In view of the practical difficulties of basic data in the power grid planning work, and combined with the present situation of information systems in power grid companies, this paper puts forward the ideas about how to design planning basic data storage, and the flow of various data in the planning management information system, with the systematic analysis method and system integration mind. Firstly, the systematic analysis and multi hierarchy architecture method was employed to design and implement the power grid planning information system. Then the data flow theory was used to optimize the data flow within the panning system and the data inflow and data interfaces with external planning data source information systems. Finally, the organization architecture of the complex planning data was also designed finally. By applying the above results, a basic database and its advanced functions have been constructed. Practical application shows that the research results of this paper can integrate the existing data resources effectively, and ensure the accuracy and timeliness of the basic data for planning, so as to support the advanced planning function efficiently.