A display device and a display controlling module are provided. The display controlling module includes a data analyzing unit, an interference data storage unit and a data adjustment unit. The data analyzing unit receives a plurality of display data of a corresponding frame, analyzes the display data to obtain a plurality of grayscale distributions of the corresponding display regions of a display panel and generates a backlight signal for adjusting a brightness of each of a plurality of light emitting groups of a backlight module according to the grayscale distributions. The interference data storage unit outputs a plurality of interferences of the corresponding display data according to the backlight controlling signal. The data adjustment unit receives the display data and the interferences and correspondingly adjusts grayscales of the display data according to the interferences.