Backlight module and display device

A backlight module, comprising:

• a light guide plate, including a light incident surface and a light emitting surface connected to the light incident surface;
• a light source, provided corresponding to the light incident surface of the light guide plate;
• a first optical film, provided corresponding to the light emitting surface of the light guide plate, the first optical film includes a body, a plurality of prisms arranged on the body and facing the light emitting surface, and a plurality of optical structures arranged on the body and facing away from the light emitting surface of the light guide plate, wherein, the prisms are located between the light emitting surface and the optical structures;
• two second optical films, stacked on the first optical film, each of the second optical films has a plurality of parallel strips facing away from the first optical film, and the direction E1 of the strips on one of the second optical films is different from the direction E2 of the strips on the other second optical film;
• and
• wherein the backlight module further includes a diffusive reflector located below the light guide plate, wherein the ratio between the prism angle of the prisms of the first optical film and the roughness of the diffusive reflector is greater than 200 and less than or equal to 250.