The present disclosure provides a method for manufacturing a display substrate, a display substrate, and a display device. The method for manufacturing a display substrate comprises: providing a container, which is positioned horizontally and which contains a curable liquid, and the bottom of which is flat; immersing a side of the substrate parallel to the bottom of the container in the horizontal direction into the curable liquid; and performing curing treatment of the curable liquid until the curable liquid is solidified on the side of the substrate to form a film layer.