A display device, comprising: an optical waveguide layer having a light-entering region and a light-exiting region; an optical element configured to emit at least two types of light beams having different image information, the optical element being arranged at the light-entering region, to transmit the at least two types of light beams to the light-entering region of the optical waveguide layer; a first coupling grating arranged on a transmission path of the at least two types of light beams in the optical waveguide layer, and configured to change a direction of each of the at least two types of light beams having entered the optical waveguide layer, to enable each of the at least two types of light beams in the optical waveguide layer to transmit in a direction toward the light-exiting region; and a second coupling grating arranged in the optical waveguide layer at a position corresponding to the light-exiting region, and configured to enable light beams formed by light beams having same image information in the at least two types of light beams to exit from the light-exiting region and be converged at a same viewpoint, and enable light beams formed by light beams having different image information in the at least two types of light beams to exit from the light-exiting region and be converged at different viewpoints, to form at least two predetermined viewpoints located within a visual range of a same pupil, characterized in that the second coupling grating comprises at least two second regions, the at least two second regions correspond respectively to at least two types of light beams formed after the at least two types of light beams have been coupled by the first coupling grating; and each of the at least two second regions comprises a plurality of ring-shaped gratings, the plurality of ring-shaped gratings are arranged on the optical waveguide layer and spaced apart from each other, and sleeved one on another, and each of the ring-shaped gratings comprises one or more second grating bars, the one or more second grating bars are arranged in a substantially circumferential direction along the ring-shaped grating and spaced apart from each other. an optical waveguide layer having a light-entering region and a light-exiting region; an optical element configured to emit at least two types of light beams having different image information, the optical element being arranged at the light-entering region, to transmit the at least two types of light beams to the light-entering region of the optical waveguide layer; a first coupling grating arranged on a transmission path of the at least two types of light beams in the optical waveguide layer, and configured to change a direction of each of the at least two types of light beams having entered the optical waveguide layer, to enable each of the at least two types of light beams in the optical waveguide layer to transmit in a direction toward the light-exiting region; and a second coupling grating arranged in the optical waveguide layer at a position corresponding to the light-exiting region, and configured to enable light beams formed by light beams having same image information in the at least two types of light beams to exit from the light-exiting region and be converged at a same viewpoint, and enable light beams formed by light beams having different image information in the at least two types of light beams to exit from the light-exiting region and be converged at different viewpoints, to form at least two predetermined viewpoints located within a visual range of a same pupil, characterized in that the second coupling grating comprises at least two second regions, the at least two second regions correspond respectively to at least two types of light beams formed after the at least two types of light beams have been coupled by the first coupling grating; and each of the at least two second regions comprises a plurality of ring-shaped gratings, the plurality of ring-shaped gratings are arranged on the optical waveguide layer and spaced apart from each other, and sleeved one on another, and each of the ring-shaped gratings comprises one or more second grating bars, the one or more second grating bars are arranged in a substantially circumferential direction along the ring-shaped grating and spaced apart from each other.