The present application discloses a backlight module and a display device. The backlight module includes a light source assembly, a light concentration structure concentrating light emitted from the light source assembly and emitting the light in a predetermined angle range, a light guide structure guiding the light concentrated by the light concentration structure in a way of mirror reflection out from a light exiting surface of the light guide structure, and a viewing angle switch assembly, wherein the viewing angle switch assembly guides light emitted from the light guide structure outward at a first viewing angle or a second viewing angle.