Abstract: In this paper, the reaction products of dibutyl phosphate in 2.0 mol/L HNO₃ of spent fuel reprocessing condition were butanol, butyric acid, propionic acid, mono-butyl phosphate, and phosphate ion, etc., determined by infrared spectroscopy, GC-MS, and ion chromatography. The relationship between the concentration of mono-butyl phosphate and phosphate ion with the reaction time and temperature was determined by ion chromatography quantitative analysis, and the rate constants of the hydrolysis reaction of dibutyl phosphate were calculated and fitted. The results show that: the hydrolysis rate of dibutyl phosphate increases exponentially with the increase of temperature at the range of 110-150 ℃, which satisfies the quasi-first order kinetic equation. The first-order hydrolysis rate constants are 6.30×10^-3 s^-1 at 110 ℃ and 2.10×10^-1 s^-1 at 150 ℃, and the second-order hydrolysis rate constants are 3.10×10^-3 s^-1 at 110 ℃ and 1.98×10^-1 s^-1 at 150 ℃, respectively. For the first-order hydrolysis reaction, the pre-exponential factor is 9.38×10¹² s^-1, and the corresponding activation energy is 111.0 kJ/mol. For the second-order hydrolysis reaction, the pre-exponential factor is 1.09×10¹⁶ s^-1, and the corresponding activation energy is 135.2 kJ/mol. The error between the calculated kinetics values and the experimental values is within ±9%.