The integration of various types of substation data is the basis for achieving substation intelligent application. The generation mechanism of various substation data and the support to data interchange by all kinds of communication protocol are analyzed. The significance of the establishment of a data center for an intelligent substation is described. The framework of the intelligent substation data center is shown. The standardization of data collection， unified storage and unified retrieval are studied. A novel method of implementing the data center is proposed. It is suggested that dynamic modeling be adopted for core data storage and the object-oriented method be used for data retrieval. High requirements are made on data quality and security management of the data center. The development potential of substations function application based on the data center in the smart grid is given.