With the rapid development of smart grid and the rapid increase of electricity load, area planning and management work is lagging behind the smart grid development, area voltage quality is poor, the line loss rate is more and more sudden, line loss calculation exact is the key for the reduction measures. In this paper, the calculation of the improved line loss and the reactive power compensation are carried out on the area. The objective function is used to calculate the approximate reactive power compensation of the area by genetic algorithm and sensitivity analysis. Finally classify the area according to the per capita sales of electricity, in each type select a typical area and then reactive power configuration program in random area is achieved through the weighted impact of the electrical characteristics of reactive power loss.