By using multi-block grid technique, wall-function method and S-A turbulent model, numerical simulation for liquid flow in inner flow field of high-speed centrifugal pump impeller with open radial impeller and open camber impeller have been done. And the simulative sample was tested and studied. After comparing and analyzing the results of numerical simulation and examination, the numerical value simulation result confirmed to the examination result that had been gained. And such simulative method was proved to be a good method to simulate the flow field in centrifugal pump impeller. Thus the variational rule of flow field in impeller caused by different impeller types was detected.