The work aims to prepare a new time-temperature indicator (TTI) of which the activation energy can be changed by adjustment of pH value based on the properties of gallic acid (GA), so as to provide reference for the development of new TTI. The GA TTIs with different GA concentrations and pH values were prepared and stored at constant temperature. The effect of GA concentration and pH value on the color change of TTIs was explored. The absorbance value of prepared TTIs was determined, and the chemical kinetic model of TTI color response was established, and their kinetic parameters and activation energy were determined. TTI was most sensitive to temperature when GA concentration was 0.02 mol/L, so four kinds of TTIs with GA concentration of 0.02 mol/L and pH value of 6.5, 7.0, 7.5 and 8.0 were prepared, respectively. At pH 6.5, the colorless TTI eventually turned into earth-yellow, at pH 7.0, the colorless TTI eventually turned into grass green and at pH 7.5 and 8.0, the colorless TTI eventually turned blue-green. The activation energies of four kinds of TTIs calculated by absorbance were 85.99, 44.93, 29.57 and 25.03 kJ/mol, respectively. The color of GA TTI changes significantly at different pH values. The activation energy of GA TTI has a large range that is suitable for a wide range of food types, so GA TTI has the potential to act as a new TTI.