The present invention provides a backlight module, comprising a light source module and an optical control layer disposed on the light source module. The optical control layer comprises a first optical film and a second optical film. The first optical film has a first overlap area on a first side, the first overlap area comprises first inner openings; the second optical film comprises a second overlap area near the first overlap area. The second overlap area matches the first overlap area. The second overlap area comprises second outer openings corresponding to the first inner openings.