An organic light-emitting diode (OLED) substrate, which includes a plurality of light-emitting sub-pixels and a pixel partition wall, wherein at least one layer among hole injection layers (HIL), hole transport layers (HTL) and organic light-emitting layers of at least two light-emitting sub-pixels has a different thickness; and upper surfaces of the HIL, the HTL and the organic light-emitting layer of any light-emitting sub-pixel are each parallel and level to an upper surface of one respective lyophilic film layer of the pixel partition wall. The OLED substrate can be used for improving the surface smoothness of each organic layer of the light-emitting sub-pixel. The embodiment of the present invention further provides a display device.