The present disclosure relates to a driving method and a driving device of display panels. The driving method includes: obtaining three-color sub-pixel data of each of pixels of a current image; obtaining a saturation value and a Chroma value corresponding to each of the pixels; determining if the saturation value corresponding to each of the pixels is within a predetermined range; obtaining a white-grayscale-added value in accordance with the Chroma value corresponding to the pixel, adopting the white-grayscale-added value as a white grayscale value of the four-color sub-pixel data corresponding to the pixel, and outputting the white grayscale value to the display panel upon determining the saturation value corresponding to the pixel is within the predetermined range. In this way, the brightness of the pure-color image displayed on the display panel may be enhanced, and there is no darker issue when the pure-color image is displayed.