A TFT, a method for driving TFT, an array substrate, and a display device are disclosed. The TFT comprises a first gate on a base plate, an active layer insulated from the first gate, a source and a drain, and a second gate arranged on a side of the active layer away from the first gate and insulated from the active layer. The second gate comprises at least two sub-gates. An orthographic projection of each sub-gate overlaps that of a channel region. The first gate is capable of controlling the complete channel region, and the second gate is capable of controlling a portion of the channel region. The first and second gates maintain an energy band of the channel region at a relatively stable state, and thus maintain stable switching characteristics. This increases reliability and electrical performance of TFT.