Provided are a manufacturing method of a display substrate, a display substrate and a display device, which belongs to the field of display technologies. The manufacturing method of the display substrate includes: forming a first planarization layer on a base substrate on which a patterned film layer is formed; forming a first buffer layer on the side, away from the base substrate, of the first planarization layer; forming a second buffer layer on the side, away from the base substrate, of the first buffer layer; and forming a Wire Grid Polarizer (WGP) on the side, away from the base substrate, of the second buffer layer.