The invention provides a display panel, a display device and a manufacturing method thereof; the display panel comprises a display area, and the display area comprises: a light-emitting subarea and anexternal light transmission sub-area; an anode arranged in the light emitting subarea; a light-emitting layer arranged on the anode and is positioned in the light-emitting subarea; a cathode arrangedon one side, far away from the anode, of the light-emitting layer and covers the display area; a covering layer arranged on one side, far away from the light-emitting layer, of the cathode; the covering layer at least covers the light-emitting subarea; by patterning the covering layer, the thickness of the original covering layer on the cathode is kept, the normal electrical performance of each film layer and the display effect of the display panel and the display device are ensured, and meanwhile, the penetration capacity of light rays of the external light transmission sub-area is enhanced,so that the transparent display effect of the display panel and the display device is improved.