A system and method for extracting a skeleton topology structure for an electric power grid, the method comprising: receiving a description of a topology sub-structure corresponding with user's need and a description of skeleton topology sub-structure extracted from the topology sub-structure; generating a first incidence matrix based on the description of the topology sub-structure and a second incidence matrix based on the description of the skeleton topology sub-structure; generating a third incidence matrix based on a primary topology structure of electric power grid; searching from the third incidence matrix a sub-matrix that matches the first incidence matrix; obtaining a fourth incidence matrix by using the second incidence matrix to transform the matching sub-matrix; and generating a skeleton topology structure corresponding to the primary topology structure based on the fourth incidence matrix.