A method for measuring a residual stress of a curved-surface bulk material includes steps of: locating a point at which a to-be-detected curved surface of a curved-surface bulk material has a highest curvature as a to-be-detected point; applying an instrument integrating an X-ray light resource and a detector, measuring the to-be-detected point by using an X-ray diffraction theory, and analyzing and calculating, in combination with a cos α method, a strain value measured by using the instrument; and calculating, in combination with material property measurement data of the curved-surface bulk material, a curved-surface residual stress by introducing a curved-surface bulk material residual stress calculation model.