OLED array substrate, making method thereof and display device

The embodiment of the invention provides an OLED array substrate, a making method thereof and a display device and relates to the technical field of display.The occupied area, in an effective display region, public power source supply lines in the OLED array substrate can be reduced, the aperture ratio of the display device with the array substrate is increased, and then the service life of the OLED display device is prolonged.The OLED array substrate comprises multiple pixel units and a metal wire, wherein each pixel unit comprises an OLED light-emitting unit, a driving transistor, a storage capacitor, an insulating layer and a metal conductive layer, the insulating layer covers the driving transistor, the storage capacitor and the metal wire, and the metal conductive layer is located on the insulating layer and used for providing public voltage for the pixel unit; the metal conductive layer and at least one of the metal wire, the driving transistor and the storage capacitor are overlapped perpendicular to the OLED array substrate.The making method is used for making the OLED array substrate and the display device with the array substrate.