Abstract: The average grain size of the large-size nickel based deformation FGH96 superalloy turbine disk in radial direction was analyzed statistically, and the corresponding hardness was characterized. The results show that the grain size increased from the center to the edge of the disk, and the hardness showed a decreasing trend. In addition, from the center to the edge of the disk, local hardness was changed in numerical fluctuations, which was affected by the shape of the turbine disk.