Based on the convenience of the use, the traditional display will be replace by the flexible display. According to this reason, it is very important to study on the reliability of the amorphous silicon (a-Si:H) thin-film transistor (TFT) used in LCD under different mechanical strain. In this research, besides of the above-mentioned we also applied AC stress, to understand the influence of AC stress on an a-Si:H TFT under different mechanical strain. The influence of mechanical strain on the performance of an hydrogenated amorphous silicon (a-Si:H) thin-film transistor (TFT) with different channel length and width on metal foil substrate under uniaxial compressive or tensile strain was studied, where the strain is parallel to the TFT source-drain current path. The process of TFT with the maximum temperature 190¢XC exhibited a field-effect mobility of 0.1 cm2/Vs and a threshold voltage of 1.95 V and the leakage current of less than 10-13 A. The TFTs were strained by inward (compression) or outward (tension) cylindrical bending. The mobility had a slightly change under the mechanical strain, which was due to the change in the disorder under bending strain. We also researched on the influence of uniaxial compressive (tensile) strain on the performance of a-Si:H TFTs under different AC stress conditions. When the a-Si:H TFTs were strained and applied AC stress, we found the performance of a-Si:H TFTs were affected more then the flat ones.