Objective To overcome the drawback of low accuracy of heuristic algorithm in solving VRP. Methods An improved vehicle routing model was built with single depot and multi vehicles. By analyzing the vehicle path problem, this paper improved the Branch and Bound method used in Travelling Salesman Problem and designed an accurate algorithm for the VRP model. Then, the algorithm was programmed by computer. At last, a case of a distribution system with one central warehouse and eight customers was taken as an example to show the effectiveness of the algorithm. Results A solution with 3 lines containing a total road length of 60 km was obtained, which saved 17 km in comparison with the result （77 km） attained using heuristic algorithm. Conclusion Using Branch and Bound method to solve vehicle and routing problem was simple to implement, and the solution was more accurate.