In order to satisfy the requirement of geometry modeling for virtual reality system, we process a modeling method based on CAD data. Firstly, the media file that is exported from the CAD data is parsed to gain the mesh data. And then the mesh data was simplified through the improved quadric error metrics algorithm, which makes better shape of triangle. At last, the mesh data is wrote to standard virtual reality model with lever of details via OpenFlight API. Experiments show that triangular mesh shape by our algorithm is more reasonable than QEM algorithm, but with higher quality of rendering. With large simplification, rendering frame rate and loading efficiency of model are high improved, and visualization of the virtual reality model almost have no change, which will be sufficient to meet the demand of virtual reality system.