Abstract: Traditional traffic planning of open pit mine is based on the shortest path,without considering the capacity of link and the degree of congestion. The result of the traffic planning has the risk of over assignment for a specific path. In order to solve this problem,based on Wardrop equilibrium principle as the theoretical basis,this paper considered the influence of road traffic flow and through capacity by introducing the comprehensive impedance concept,and estab- lished a road network equilibrium assignment model of truck flow in open pit. It realized in the optimization of road traffic based on the traditional traffic planning. The experimental results showed that when the network equilibrium model is not considering the road comprehensive impedance,the allocation result was consistent with the traditional traffic planning. When considering the road resistance,the flow of the traffic was at a minimum total time so that it minimized the situation of road congestion. It is proved that the model has the versatility and practicality for further op- timize the truck dispatching system.