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This paper presents a new method to calculate the bending moments in varied curvature sheet bending. Compared with traditional bending theories which suppose the curvature radii to be constant, the new formulas of stress and strain consider the geometrical characteristics of the profiles, thus they can reflect the internal force in the sheet more accurately. Also, they are consistent with traditional bending theories when the curvature remains unchanged. Springback predictions are performed based on the calculated bending moments. The final shapes of the sheet after springback are obtained by proper discrete and connecting technologies. Two cases are provided to demonstrate the calculating method. In the first case, a cubic non-uniform B-spline curve is used to interpolate the known die profile. This curvature continuity spline gives a relatively accurate expression of the curvature change phenomenon. In the …