Organic light-emitting diode (OLED) display substrate and display device

The invention provides an organic light-emitting diode (OLED) display substrate and a display device, belonging to the technical field of display. The OLED display substrate comprises a plurality of sub-pixel regions with different colors, wherein the plurality of sub-pixel regions are formed on the substrate, each sub-pixel region comprises a thin film transistor, a positive electrode, a light-emitting layer and a negative electrode which are sequentially arranged in a direction far away from the substrate, a micro-cavity structure is formed between the positive electrode and the negative electrode, the positive electrode comprises a hollow part, the light-emitting layers of the sub-pixel regions with different colors have different thicknesses, or the positive electrodes of the sub-pixel regions with different colors have different thicknesses. With the technical scheme provided by the invention, the influence of ambient light can be reduced on the condition that no polarizer is attached, thus, the polarizer attachment can be omitted, and the light utilization ratio of an OLED display device is further improved.