Abstract: A method for forming a large-size curved thin-walled metal skin is disclosed, wherein the position and size characteristics of stiffeners on a curved panel is extracted; the thickness of the curved panel and the thin-walled skin after assembly is assumed to be m, and a forming surface of the punch is offset outwards along a normal line by the thickness m to obtain the characteristics of the inner surface of a female die; the number of the discrete support moulds is set to be the same as the number n of the stiffeners based on the size and distribution of the stiffeners on the curved panel; and the punch and the female die combined with the discrete support moulds are used to carry out stamping of a curved thin-walled slab to obtain a required thin-walled skin component.