The present invention relates to a sectional dynamic-driving backlight module and a head-up display device thereof. The sectional dynamic-driving backlight module comprises an optical-directional lens unit and an optical-homogenizing unit. The optical-directional lens unit is provided for converging the light beams emitted by the light source assemblies in the backlight module into light beams with a smaller divergent angle, and the optical-homogenizing unit is used for further homogenizing the light beams, so as to make all display regions of the LCD show a uniform illumination. Therefore, all images showed on an eyebox of the driver are distinct. Besides, each of the light source assemblies consist a red-light LED chip, a green-light LED chip, a blue-light LED chip, and a white-light LED chip, and these LED chips may be controlled by a controlling PCB for lighting respectively or simultaneously, so as to achieve a sectional dynamic display.