Abstract: In numerical simulation of geotechnical engineering,it is necessary to establish model according to complex engineering geological condition.Modeling is so troublesome that numerical model is often simplified in engineering practice.However,the accuracy and reliability of the calculated results are directly influenced by the characteristics of the model.Thus,the researches on modeling method for numerical analysis are necessary.On the other hand,the 3D geologic model can better reflect the actual geological conditions.With regard to such problem,a new and practical modeling method(CRM Geologic Model Transforming Method) of numerical analysis by combining geologic model and numerical model was presented.This method was implemented using the following procedures: ① cutting the 3D geologic model according to numerical calculation region;② extracting control data from the cut model to reconstruct the model mesh;③ forming the numerical model automatically by the stratum attribute;④ importing the model into numerical analysis system and finishing the modeling work.All procedures were carried out rapidly by programming.In the method,the excavation process could be simulated conveniently and the complex model could be used in different numerical systems.It was proved that the method was more accurate and simple and the efficiency of preprocessor was highly improved.Some useful references would be given by the proposed technology to the continuous researches on this subject.