In order to study the catalytic effects of manganese-loading sludge activated carbon on oxalic acid wastewater degradation in the catalytic ozonation processes and to explore a new way on resources recovery of sludge, the continuous flow of ozone oxidation methods were conducted in the expereiments, and the main influence factors and the best reaction conditions of manganese loaded sludge activated carbon catalytic ozonation were investigated by the single factor experimental methods, and the reaction mechanisms of catalytic ozonation were discussed. The results demonstrated that the oxalic acid wastewater had the highest removal rate at 91.2% within 60 min under the best reaction conditions of the ozone concentration being 5.0 mg/L, the dosage of manganese loaded sludge activated carbon being 100 mg/L, and the pH being 3.5. Tert-butyl alcohol had inhibitory effects on degradation of oxalic acid, catalytic ozonation conforms to hydroxyl free radical reaction mechanism. The treatment effects of the method was obvious and itis a significant reference to evaluate the effects of catalytic ozonation.