The invention provides a method for designing a roll shape of a variable-crown working roll which is used for plate shape control in strip steel production and has quartic crown control capacity. By using the method, the approximate linear relationship between a no-load roll gap quadratic crown and the channeling shift amount of a roll is ensured, and simultaneously the quadratic crown capacity of wide and narrow strip steel can be balanced. By utilizing the corresponding relationships among roll shape coefficients provided by the invention, a variable-crown roll shape of a quintic polynomialfunction can be designed flexibly according to the requirement on quadratic and quartic crown control. The method has the characteristics that: the roll shape designed by the method can change the characteristic that a quadratic crown control range is in square drop along with the reduction of the width of the strip steel. Compared with a cubic CVC roll shape, the roll shaped designed by the method can not only provide the quartic crown control capacity, but also provide higher quadratic crown control capacity. Compared with a quintic CVC roll shape designed by other methods, the method has convenient design, can design flexibly according to the requirement on the quartic crown control, and can balance the quadratic crown control capacity of the wide strip steel and the narrow strip steel.