Using γ-Al2O3 as carrier, Mn-Ce/γ-Al2O3 was prepared by ultrasonic impregnation method, and it was used as catalyst to treat high-concentration and high-salt chlorpyrifos wastewater by catalytic wet air oxidation. The catalytic materials were characterized by FTIR, XRD, SEM. By single factor experiment, this paper discusses the reaction temperature, pH, catalyst dosage, the dosage of oxidant on the influence law of COD removal. The uniform design method was used to optimize the experimental conditions of catalytic wet air oxidation, when the influent COD concentration is 13550 mg/L, the optimal conditions of wet catalytic oxidation are as follows: reaction temperature is 230 oC, reaction time is 2 h, influent pH is 7, dosage of 30% hydrogen peroxide is 5.5 mL, dosage of Mn-Ce/γ-Al2O3 catalyst is 0.4 g, under this condition, COD removal rate reaches 90.63%; the primary and secondary order of various factors affecting the experimental results is reaction temperature > amount of catalyst > amount of oxidant > time. The density functional theory method is used to calculate the quantum chemical parameters of chlorpyrifos molecule, combined with free radical capture experiment and the results of the UV spectrum, the possible mechanism of catalytic wet air oxidation degradation of chlorpyrifos was preliminarily discussed. the results show that, MnO2 and CeO2 active components are loaded on γ-Al2O3, Mn-Ce/γ-Al2O3 can better promote H2O2 to produce •OH, and The kinetic experiments show that the degradation process of COD by catalystic wet air oxidation is in line with the quasi-second-order kinetic equation.