The invention discloses a 220kV urban ring network partitioning method based on a node set GN splitting-up algorithm, and the method comprises the following steps: obtaining a source node from an urban ring network, and forming a node set NodeSet; obtaining edge betweenness through employing a conventional GN splitting-up algorithm according to the source node, enabling a 220kV circuit number to serve as an edge weight, and obtaining comprehensive edge betweenness of all edges of the network; continuously removing the edges with the maximum comprehensive edge betweenness till there is no partitioned region in the network, forming a preliminary ring network partitioned structure, and forming a preliminary 220kV urban ring network partitioned scheme. The method has few human factors, is more objective and accurate in formed scheme, has effective theoretical support, and fits the actual conditions.