With the establishment of each business system platform of power grid planning and the rapid increase of heterogeneous business data,  the barriers are badly needed to be broken between business system platforms to establish a perfect business information sharing and interaction system. Based on the analysis of the existing business system data format and the status quo of storage situation, this paper researches the key technology of heterogeneous data integration and storage, and proposes a cross-platform power grid planning data fusion and storage pattern. Heterogeneous data have been fused by establishing a unified business data information model. The distributed file storage system has been established based on Hadoop to implement fast and efficient storage and index of massive heterogeneous data. Thus, the research results can provide theoretical guidance and architecture support for massive heterogeneous data and information sharing in power grid planning system and electric power industry.