The invention relates to a method for equivalently simplifying and regenerating memory bank indexes for an electrical power system, which belongs to the technical field of topological designs for electrical power systems. The method comprises the following steps of: backing up the complete information of the initial node and line segments of a memory bank, and adding flag bits for judging whether nodes and the line segments need to be combined; setting the flag bits of the nodes and the line segments according to the result of equivalent simplifying for the line segments; determining the indexes of the simplified nodes according to the flag bits of the nodes, and establishing a new node mapping table and an old node mapping table; emptying all data in the node table of the memory bank, and sequentially writing the nodes with the flag bits which are equal to 0 in the node table of the memory bank to regenerate data; emptying all data in the line segment table of the memory bank, and sequentially writing the line segments with the flag bits which are equal to 0 in the line segment table of the memory bank to regenerate line segment table data, and updating the mount node indexes of equipment such as loads, capacitors and power supplies in the memory bank. According to the method disclosed by the invention, the problem that lots of nodes and line segments are still mounted in the network-simplified memory bank is solved, and the reliability of the memory bank is improved.