In order to eliminate the image sticking in high-temperature of TFT-LCD, a method to improve image performance by adjusting the positive and negative Gamma voltage and a quantitative research is conducted. The method of asymmetric adjustment of positive and negative Gamma voltage is quantified. Aiming at the problem of image sticking in the LCD field, an electrical principle is analyzed, which is the reason why the image sticking is inevitable in LCD, and a method to quickly adjust the positive and negative Gamma voltages is proposed. The Flicker value is measured in a normal or high temperature environment to determine the variation of Vcom voltage. According to this variation, the positive and negative Gamma voltage of the LCD are ajwsted, so as to realize the quantitative theoretical value to adjust Gamma voltage, and finally achieve the goal of eliminating the residual image. The experimental result shows that the residual image level is reduced from L1 to L0.5 by this method.