According the embodiments of the present disclosure, the light guide plate includes a light guide plate body having an upper surface as a light-exiting surface. The light guide plate is provided at a side portion at least one notch, and a light-reflection layer is arranged at a surface of each notch. A wedge-shaped structure is arranged on a lower surface of the light guide plate body and adjacent to a bottom of each notch. The wedge-shaped structure has a first surface attached onto the lower surface of the light guide plate body, a second surface serving as a light-entering surface, and a third surface intersecting the first surface and the second surface and forming an acute angle relative to the first surface. A light-reflection layer is arranged on the third surface. A light source is arranged at a position on the lower surface of the light guide plate body adjacent to the second surface of the wedge-shaped structure.