The present disclosure relates to a driving method and a driving device of display panels. The driving method includes: dividing a saturation interval of an original image frame to be displayed by a display panel into a plurality of sub-saturation intervals; obtaining saturation values corresponding to each of the pixels in the original image frame; calculating numbers of pixels in the original image frame falling within each of the sub-saturation intervals in accordance with the saturation values corresponding to each of the pixels. In this way, the backlight brightness outputted by the backlight module may be adjusted in accordance with the saturation values of the original image frame so as to enhance the low brightness issue when a pure-color image is displayed by the display panel configured with RGBW sub-pixels.