Preliminary design calculation flow charts of vehicle centrifugal compressor are constructed, and the optimization calculation modeling and performance predication modeling of vehicle centrifugal compressor is established. The modeling on the calculation and performance simulation is practiced in actual design. By using this calculation model, the preliminary geometry parameters in compressor can be determined, and optimization strategies can be formed, and also the performance of centrifugal compressor in design condition and off-design condition can be simulated. The method can be used in the selection, preliminary design, and parameter optimization and performance simulation on vehicle turbocharger centrifugal compressor.