Routing allocation scheme is a core issue in agricultural machinery allocation. It is related to the allocation cost, income and timeliness of crop harvest. How to select a farmland spot to harvest, which needs to consider not only the distance between a farmland spot and an agricultural machinery spot, but also road condition, farmland area, types of agricultural machinery and weather conditions. It analyzes the main influenced factors of routing selection solution in agricultural machinery allocation and has built an improved hierarchy analysis model about these influenced factors in this paper. For the uncertain influenced factors or influenced factors with incomplete information, it adopts an improved fuzzy hierarchy analysis method to evaluate the factor weights in the paper. And the resolving power is improved and the believable degree of the routing selection solution is increased. The evaluation model has supplied a good scientific basis for further research.