Display substrate, preparation method thereof and display device

The invention provides a display substrate, a preparation method thereof and a display device. The display substrate comprises a substrate; the metal conductor layer is located on the substrate, and the metal conductor layer comprises a bonding pad; the protection layer is located on the side, away from the substrate, of the metal conductor layer, an opening is formed in the protection layer so that the bonding pad can be completely exposed, at least one flow guide structure is arranged on the side wall of the opening, and the flow guide structure comprises a flow guide channel which is obliquely arranged in the direction away from the opening. Due to the fact that the flow guide channel is obliquely arranged in the direction far away from the opening, in the vertical line body production process, after the display substrate is vertically arranged, residual liquid medicine of the previous process in the opening can slowly flow out in the direction far away from the opening along the flow guide channel, and the residual liquid medicine cannot be continuously accumulated in the opening; therefore, the subsequent process is not affected, the stability of pad surface treatment is improved, and the product yield is improved.