Abstract: Residual stress of central rolling part and margin rolling part of nuclear power rotator after rolling treatment was investigated by X-ray diffraction method, and the residual stress distribution was also studied. The results show that at the central rolling part, the average residual stress was -464.8 MPa in axial direction, and was -454.4 MPa in circumferential direction. The residual stress distribution was uniform, and the strengthen effect was obvious. Compared with the central rolling part, at the margin rolling part, the residual stress was lower, and residual stress values were closed and uniform distributed in axial and circumferential directions.