The invention relates to a power grid data modeling method based on graphical interactive operation and a system thereof. The method comprises the following steps: leaving-factory parameters of a power grid data modeling element device are gathered, and a typical parameter library for the power grid element device is built; a substation and a line are abstracted and packaged, and a common template library comprising a substation template and a line template is built; the substation template and the typical parameters are used for newly building substation data; the line template and the typical parameters are used for newly building line data; and large-scale power grid modeling based on graphical interactive operation is carried out, and simulation analysis and modeling are carried out at the same time. Compared with a power grid data modeling method based on a text, a sheet and a single-line diagram, the method is more efficient in the case of building a large-scale power grid, and the power grid element parameter filling method based on the typical parameters also simplifies the power grid data modeling difficulty.