The present disclosure relates to a display substrate, a fabricating method thereof, and a display device, which belong to the field of display technology. The display substrate comprises: a base substrate, and a first light emitting unit disposed on the base substrate, the first light emitting unit comprising: a first selective reflection transmission layer, an anode layer, a first organic light emitting layer, a cathode layer and a reflective layer, superposed sequentially, wherein the first selective reflection transmission layer and the reflective layer are capable of reflecting color light emitted from the first organic light emitting layer, so that the color light oscillates between the first selective reflection transmission layer and the reflective layer, and exits the base substrate via the first selective reflection transmission layer. The embodiments described herein can improve the light outgoing efficiency of the display substrate and the display device made of the display substrate.