The invention discloses a method for optimizing display colors of a display device, respectively regulating six primary colors of the display device at different brightness levels, where the six primary colors consist of red, green and blue tricolors and three primary colors; dividing possible 0-1.0 interval of saturation distribution of each color component of a input signal into plural independent intervals; in each independent interval, according to characteristics of display and related circuits, selecting different correction coefficients to avoid loss of oversaturated and undersaturated highlight details, where the correction coefficients form a continuous broken line of saturation distribution. And the invention makes nonlinear regulation on saturations of different color components of each pixel according to correction coefficients of the broken line so that the output can not be oversaturated and the undersatruated highlight details can not be lost; and the invention uses four-segment broken line to approximately make nonlinear correction, reducing operational complexity and optimizing the display colors of a display device.