Take the unitary minimal investment and annual operating cost of multi voltage grades for the objective function, adopt the line length calculating means of rectangular and adaptive mutation particle swarm optimization algorithm to make sure number and position of substations, the capacity and number of transformers, the power supply range of substations. Based on Maplnfo platform, deal with geography information of substation planning involved factors by visual, off-line processing method, create the map layer of feasible plots and append it to iterative formula as constraint condition, this method can ensure scientific and utility of optimization result in economy and geography. At the same time, it proofs efficiency and correctness of algorithm through examples.