The present disclosure provides a backlight substrate, a manufacturing method thereof, and a display device. The backlight substrate includes: a base substrate; a plurality of first light emitting elements on the base substrate and configured to emit first light; a plurality of second light emitting elements on the base substrate and configured to emit second light having a different wavelength from the first light; a plurality of depth sensors on the base substrate and configured to receive the second light emitted from the plurality of second light emitting elements and reflected by an object and determine depth information of the object based on the received second light; and a diffusion layer in direct contact with light emitting surfaces of the plurality of first light emitting elements and configured to diffuse the first light emitted from the plurality of first light emitting elements.