Abstract: The power grid construction and transformation involve a wide range of aspects,and exist the characteristics of diverse data formats and multi-directional data sources. Integrating the data involved in the system and integrating it into a unified system can improve the value of data utilization and establish a reliable and practical system. Based on these,the data in the smart construction of power grids was classified. These data included the structured,semi-structured,and unstructured data. It integrated the general model of multi-source and multi-type data,created a unified interface library for different types of data,and designed a unified fusion model for multi-source heterogeneous data to promote the fusion and unification of data with different sources,data patterns and data structures. The main steps of the heterogeneous data fusion model were data acquisition,data integration,relationship establishment,storage and call. Aiming at the types of data in the construction of the power grid,in the preprocessing stage of the model,the process of obtain data and the internal preliminary integration of various types of data was completed. Around the multi-source heterogeneous data unified fusion model,the derivation of a number of power grid construction related smart systems were researched,which included the advancement of the preliminary work of the power grid engineering construction and the smart preliminary system for data processing. In the power grid smart early-stage system,the multisource heterogeneous data unified fusion model could effectively complete the system’s unification and integration of the involved multiple heterogeneous data,and provided a new way of working for power grid engineering construction. This new way effective improved the communication efficiency of all parties in the process of power grid construction,reduced work intensity,and enhanced the standardization of power grid construction projects and the digitalization of data.