The present disclosure relates to a color gamut mapping method and a color gamut mapping device. A color gamut mapping method may include converting, by a color space converter, first three-color signals into a first luminance component and a pair of first chrominance components and outputting the first luminance component and the pair of first chrominance components, controlling, by a saturation controller, a saturation of the first chrominance component for each control area using a saturation gain of the saturation controller and outputting a second chrominance component, controlling, by a hue controller, a hue of the second chrominance component for each control area and outputting a third chrominance component, interpolating, by an overall controller, a set value of a luminance gain using grayscale differences between the first three-color signals, outputting a second luminance component by controlling first luminance component using the interpolated luminance gain.