This paper presents a new CAD model reconstruction method for finite element mesh analysis. It has been accepted by many researchers that modification of a model is often a necessity as a precursor to effective mesh generation. We design an IGES surface model transformation and repairing method based on trimmed B-spline surface patches, and give an algorithm for reconstructing Brep model from surface model without correct topology information. In processing Brep model for numerical simulation, the critical issues involves the rectification of geometrical and topological errors, clearing up sharp edges and cracks, geometry healing will be emphasized. Our model-healing algorithm essentially simplifies the problems of the imperfect models and allows one to deal with simple surface model rather than complex surface representations for finite element mesh.