Based on CAD-CFD software Francis hydro turbine runner blade optimization is studied;combined with CFD,the overall performance optimization for runner is realized by using Workbench /BladeGen Parametric modeling. Firstly Francis hydro turbine runner with a suitable water head from140m to 170m is designed by according to the 2D Design Theory. On the basis of the flow field numerical analysis results,the flow pattern is eventually improved and the efficiency is increased by using the geometric parameters controlled and optimized by BladeGen. The structure parameters of the runner could be easily controlled by BladeGen,and the research of the complex relations between structure and performance of the Francis hydro turbine can be conveniently conducted,which has a good application prospect in the design of hydraulic machinery.