For 49 as outlets in the city urban problems and analysis, and the best path of roads damaged, with the minimum total cost and the supplier does not become a breakthrough point, through the branch and bound, comparative method, respectively, established a 0-1 integer linear programming model, the incremental cost priority model. Using Matlab, Lingo11 software it is concluded that the eight best supply the city and make each other a 25% increase in total cost when 6 road.