A surface light source, comprising a waveguide layer and a grating structure; the waveguide layer has a first surface and a second surface opposite to each other; the grating structure is provided on the first or second surface of the waveguide layer; and the grating structure is used for guiding light incident to the grating structure to the waveguide layer and performing total reflection propagation in the waveguide layer. Such surface light source structure enables energy and direction of light emitted from a light field modulation layer to be distributed uniformly, and thus the thickness of the surface light source and the number of LEDs in the surface light source are reduced. Also disclosed is a display device.