Abstract: To convert complex B-rep model to shell mesh for finite element analysis effectively, a modeling approach based on pure virtual topology（PVT） is presented. PVT modeling firstly uses four operators： Merge, Split, Insert and Collapse to convert B-rep model to PVT model. Then automatically mesh the PVT model by optimized meshing algorithm based on constraints list. Experiments show that this method can quickly and robustly generated well defined 2 D mesh for real complex model, and it builds solid fundamental for the following finite element analysis.