An augmented reality (AR) display device includes a display engine configured to project light of an image, and a waveguide configured to receive and output the projected light. The display engine includes a light source unit, a reflective display panel, and a projection optical system. The projection optical system includes an iris and a projection lens group arranged between the iris and the reflective display panel. The light source unit includes a light source or a light exit end positioned near the iris in a position deviating from an optical axis of the projection optical system, such that an incident angle range of light incident to the display panel does not overlap with a reflection angle range of light reflected from the display panel. The iris includes an effective opening through which light reflected from the display panel passes.