a light guide plate, the light guide plate is provided with a light emitting surface, a bottom surface arranged opposite the light emitting surface, and a light incident surface connecting the light emitting surface with the bottom surface, the light emitting surface is divided into a light emitting region and a peripheral region surrounding the light emitting region;

a lamp bar having a light emergent direction facing the light incident surface; and

a circuit board connected with the lamp bar and positioned at a side of the bottom surface of the light guide plate, wherein a region where the circuit board is connected with the lamp bar serves as a connection region, and an orthographic projection of the connection region on the light emitting surface completely covers in the peripheral region and at least partially covers the light emitting region;

wherein a surface of a side of the circuit board facing the light guide plate is provided with a reflective layer, and the reflective layer is located in the connection region;

a reflective plate is provided in the light emitting region except for a region that overlaps with the orthographic projection of the connection region on the light emitting surface, and the reflective plate is positioned at the side of the bottom surface of the light guide plate;

a sum of a thickness of the reflective layer and a thickness of the circuit board in the connection region is equal to a thickness of the reflective plate.