The invention provides a method for improving threshold voltage of oxide semiconductor TFT, by bending the oxide semiconductor TFT for a default number of times or bending the oxide semiconductor TFT for a default duration, by bending the oxide semiconductor TFT to compress or stretch the oxide semiconductor layer to change the distance among the atoms in the channel of the oxide semiconductor TFT so as to change the energy difference between the inter-atom bonding orbital and anti-bonding orbital, resulting in controlling the threshold voltage of the oxide semiconductor TFT within a proper range to achieve improving the threshold voltage of the oxide semiconductor TFT.