The present invention provides a backlight, a display panel and a display device, The backlight includes: a first light source and a second light source, the brightness of light emitted from the first light source is different from that of light emitted from the second light source; and a light guide plate, the first light source and the second light source are disposed above the same end surface of an edge of the light guide plate, and light-emitting surfaces of the first light source and the second light source face the end surface of the edge of the light guide plate, a light mixing structure is disposed on the end surface of the edge of light guide plate and is capable of mixing the light emitted from the first light source and the light emitted from the second light source into light with uniform brightness.