Through the study on multilevel, multivariate in the evaluation on the quality of geological investigation drilling for railway engineering, the comprehensive evaluation index system hierarchical model is established for investigation drilling quality of railway engineering, the weight of each affecting factors is determined by AHP and the drilling quality of railway engineering is judged on the basis of the basic principles fuzzy mathematics. In the evaluation modle, the quantitative and non quantitative indexes which affect the drilling operation quality of railway engineering are comprehensively taken into account; taking the hole formation conditions, drilling record, situ measurement as basic criterion layer, based on the situ jugdement, each index layer under criterion layer is determined, which is then converted into membership matrix according to evaluation grading standards, the comprehensive evaluation on drilling quality grade for railway engineering is made by fuzzy mathematics principle.