A method for manufacturing a display backplane, a display backplate, and a display device are disclosed. The method includes: forming a planarization layer on one side of a substrate inside a pixel region, a partition region, and a perforation region; forming at least one girdle of annular passivation layer disposed around the perforation region on a surface, away from the substrate, of the planarization layer inside a portion of the partition layer; removing a portion of the planarization layer, inside the partition region, uncovered by the annular passivation layer and the planarization layer, inside the partition region, partially covered by the annular passivation layer, to obtain at least one girdle of annular isolation columns disposed between the substrate and the annular passivation layer and around the perforation region; and forming organic light-emitting elements on one side of the planarization layer away from the substrate to obtain the display backplane.