The present disclosure provides a display substrate, a fabricating method thereof, and a display device. The display substrate includes a substrate; at least one pixel on a side of the substrate, the at least one pixel comprising a driving transistor, the driving transistor comprising a drain; an insulating layer on a side of the driving transistor away from the substrate, the insulating layer covering the driving transistor and having a first via hole opposite to the drain; an auxiliary conductive structure on a side of the insulating layer away from the substrate, and the auxiliary conductive structure connected to the drain through the first via hole; and a first planarization layer on a side of the auxiliary conductive structure away from the substrate, and having a second via hole disposed therein.