The geographic coordinates of loads are converted into screen coordinates to show on the screen by GIS technology, according to the power load distribution density condition, the plan area is divided into several small areas(partial areas) by man-machine conversation. First, the initial main trunk line is formed in every partial area making use of least square method. On the basis of that, the power loads of the area are linked according to the shortest path method, thus an initial network frame of every partial area is formed. Then the initial network frames are amended continuously to form the optimal network frames with the least aim functions. Last, an optimal network frame of the whole area is formed by linking the optimal network frames of all partial areas. The method combines optimizing theory with GIS technology closely, and decomposes complex problem into simple problems. The real example planning result indicates that the planning method is intelligent, fast and effective.