Abstract: FLAC3D program is very suitable for solving the large deformation problem,having its special significance especially in elasto-plastic analysis,large deformation analysis of material,simulating construction process and other fields.But modeling and mesh generation method of non completely visualization greatly limits generality of FLAC3D.In order to establish complex geological body of model,in this paper the authors generate FISH script by writing MATLAB interface program.And it shows the feasibility and efficency of the modeling method with the case study in Tianzi Temple tunnel.