A backlight module comprises a light source, a light guide plate and at least one transparent light guide structure. Each transparent light guide structure comprises a first surface adjacent to a side of the light guide plate and a second surface far away from the light guide plate, a light emitted by the light source is directed into the first surface of the transparent light guide structure through the light guide plate. Each transparent light guide structure is configured to change a propagation direction of a first light in the light emitted by the light source, so that an emergence angle of the first light emitted from the second surface is smaller than an incidence angle of the first light incident from the first surface. The incidence angle of the first light onto the first surface is less than 90 degrees.