A light guide assembly, a light collimation assembly, a backlight module and a display device are provided. The light guide assembly includes a first prism sheet, a dielectric layer and a second prism sheet sequentially laminated, a light refractive index of the dielectric layer is smaller than that of the first prism sheet and that of the second prism sheet, the first prism sheet includes a light incident side surface, and a first plane and a first prism surface, the first plane is closer to the dielectric layer, and the first prism surface includes first prism portions extending along a second direction, the second prism sheet includes a second plane and a second prism surface, the second plane is closer to the dielectric layer, the second prism surface includes second prism portions extending along the second direction, and the second prism portion has a reflection surface.