The present disclosure provides a fabricating method of an array substrate, comprising: forming a pattern comprising a light shading member; spreading an organic material solution; solidifying the organic material solution, to form a buffer layer; forming a pattern of an active layer on the buffer layer, wherein a position of the active layer corresponds to a position of the light shading member; and forming a gate pattern, where the gate pattern is located on the active layer and is insulated from the active layer. Correspondingly, the present disclosure further provides an array substrate and a display device.