A backlight module has a light guide plate, a notch structure, a light absorption layer, and at least one light source. The light guide plate has a light-emitting surface and at least one side surface forming an angle with the light-emitting surface. The notch structure is continuously formed on the side surface and concave towards the inside of the light guide plate. The light absorption layer is distributed on an area substantially overlapping the notch structure, and the light source is stored in the notch structure.