Abstract: (Aim) In order to clarify the mechanism of oxidative gel degradation of monomer-polymerised gels at the end of temporary plugging operations, a kinetic study on the oxidative gel degradation of gels was carried out. (Methods) Using the Horowitz-Metzger, Coats-Redfern and Flynn-Wall-Ozawa models, the degradation kinetic parameters of ultra-high-strength gel (USGel) were calculated, and the degradation kinetic model suitable for USGel was obtained by comparative analysis; combining with the scanning electron microscope, Fourier infrared spectroscopy analysis and other experiments, the mechanism of the degradation of USGel by breaking of gel breakers was revealed, were obtained by using Semenov's equation to obtain the modified degradation prediction model for low, medium, and high temperatures, which was suitable for predicting the time of degradation at medium and high temperatures of USGel by analysing the experimental data; and the degradation mechanism was clarified, the The gel-breaker gradually consumes the chemical bonds such as amino group (-NH₂) and hydroxyl group (-OH) of amide group and carboxylic acid group in USGel, and the polymer molecular chain is gradually broken, and finally USGel is broken into liquid. (Conclusion) The results of the study provide a theoretical basis for the improvement of the temporary plugging and breaking technology of oil and gas wells.