The present disclosure provides a TFT, an array substrate and a fabricating method thereof and a display device. The TFT includes a gate, an active layer, a first electrode and a second electrode, the first electrode is arranged at one side of the active layer, the second electrode is arranged at the other side of the active layer, the first electrode, the active layer and the second electrode forms a stacked structure, the gate is arranged to surround the stacked structure, and the gate and the stacked structure are insulated and separated from each other. Under fixed occupation area, the conductive channel of the TFT of the present disclosure has increased width, so drain current in saturation region is increased without impacting aperture ratio of a display panel, which further optimizes performance of the TFT and the array substrate, and improves display effect of the display device.