A display device driving method and the display device are provided. The display device driving method determines a driving voltage value of each backlight unit based on a content to be displayed by a display unit corresponding to each backlight unit, achieving dynamic adjustment of luminous brightness of the backlight unit according to the display content of the corresponding display unit. Meanwhile, the driving voltage value is related to a noise in an image. Therefore, a better backlight brightness value can be obtained by reducing an influence of the noise on the adjustment of the luminous brightness.