Abstract:Because of its large size, high precision and large production volume, high precision large guide vane is a difficult problem in the manufacture of large hydraulic turbine.It is difficult to detect the cylindricity and total runout.Considering the impact of self weight and asymmetry on both sides of the leaf to the test data, through finite element analysis, the theoretical data and three coordinate measurement data were consistent,so it was determined the method that using laser tracker and vanes AB axis vertical setting was used to minimize the measurement error caused by the gravity deformation.Aiming at the data processing, the new method was used to break through the original calculation method.