The residual stress in cold rolling could decrease the accuracy of ring parts. Because many factors could cause residual stress, it’s difficult to calculate it theoretically. At present, a measurement method was generally used to study the residual stress. For example, X ray could be used to measure residual stress in rings. Through the measurement of residual stress, it could not only obtain the residual stress level after ring rolling, but also validate the finite element model to predict the residual stress distribution. However, because the ring surface was circle, it needs to cut a plane for X ray measure, and it increases measurement inaccuracy. This method only could be suited for qualitative analysis of residual stress in cold ring rolling, and it is not suitable for quantitative analysis of residual stress distribution.