As the active layer of TFT， the quality of the IGZO film is very important. IGZO deposition process was investigated and studied to improve the uniformity and stability of the V_th in IGZO TFT process. Firstly， the position of the glass was adjusted to ensure that it was in the middle of the mask. The effect of the angle on the improvement of the uniformity of the thickness of the IGZO film was analyzed to ensure the best magnet swing angle. Finally， the stability of the V_th in the IGZO TFT was ensured by controlling the oxygen pressure in the IGZO process.