An optical collimation assembly, a backlight module and a display device are disclosed. The optical collimation assembly includes: a collimation film including a light incident surface and a light exiting surface; and a light modulation component, located on the light incident surface of the collimation film and includes a plurality of light modulation portions arranged in an array. Each of the plurality of light modulation portions includes: a first surface; a second surface; and a third surface intersecting both the first surface and the second surface, an included angle between the third surface and the first surface is an acute angle, wherein the third surface is configured to reflect light entering the light modulation portion from the second surface, such that the light being reflected exits from the collimation film along a direction substantially perpendicular to the light exiting surface.