The embodiment of the invention provides a power grid panoramic modeling method and system, and the method comprises the steps: obtaining a core model and an application system model of the power grid, expanding the application system model on the outer side of the core model based on the general standard of a power system by taking the core model as a backbone, and constructing the panoramic model of the power grid. Through constructing the panoramic model of the power grid, the unified maintenance and management of the power grid model are realized, and the information sharing of each application system is realized. Moreover, by adopting the general standard of the power system, the device difference of different manufacturers can be avoided, and a data basis is provided for the intelligent analysis of power grid fault diagnosis.