This paper sets an evaluation index system of military transportation path viability according to military transportation features such as rapid, accurate, secure and concealment. It considered the information in five areas that includes the length of the path, the passage time, the unit cost of transportation, the natural conditions of the path and the capacity of the path. Then it builts the model of military transportation path selection adaptively for the greatest viability according to grey evaluation theory. The selected path could meet the requirement of military transport and achieve military transportation purpose.