Based on the limited capacity system [M/M/c]: [∞ / ∞ /FCFS]queuing model,the process mechanized waste disposal in open pit mine are analyzed,a grey evaluation model in which the purchase cost,disposal capacity,operation cost and average useful life of vehicle are comprehensively took into account is constructed. The allocation of vehicles is determined by the mod- el,and an experimental study is given for verifying the proposed model,the results show that the purpose of optimizing the allocation of vehicles can be reached by this model. Finally,some sug- gestions to improve traditional queuing model are putted forward.