This application relates to an image processing method of a display device, The method includes: dividing a picture of a display device into several main pixel blocks and several sub pixel blocks; adjusting white dot coordinates by using a gamma module; obtaining a high-voltage grayscale lookup table by using a high-voltage gamma module and obtaining a low-voltage grayscale lookup table by using a low-voltage gamma module; selecting to output the high-voltage grayscale lookup table or the low-voltage grayscale lookup table by using a first selection module; calculating a color saturation of the picture of the display device by using a color saturation calculation module; and adjusting, by a second selection module, a chromatic visible angle value in the display device according to the color saturation and the white dot coordinates, the high-voltage grayscale lookup table or the low-voltage grayscale lookup table.