Heterogeneous Mn₃O₄/CuMnO₂ catalyst CMO-A is prepared by a one-step hydrothermal method using cupric chloride dihydrate and manganese chloride tetrahydrate as raw materials.The composition of the samples prepared at different temperatures is analyzed by X-ray diffraction analysis.Using mercury lamp as light source and 50 mg/L Rhodamine B(RhB) solution as contaminant model,the photo-Fenton reaction performance of the prepared CMO-A sample is tested.The results show that CMO-150 has the best degradation effect on RhB solution when the reaction temperature is 150 ℃,and the degradation rate reaches 98.01% when the reaction time is 15 min.The optimal reaction conditions and cyclic stability of CMO-150 catalyst are investigated.The experimental results show that the optimal reaction conditions are 0.2 mol/L H₂O₂,50 mg CMO-150 catalyst,50 mg/L RhB solution and pH=3.0.After 5 cycles,the degradation rate only decreases by 22.24% at 15 min.The main active species in the reaction is hydroxyl radical (·OH) through the sacrificial agent experiment,and the reaction mechanism is explored by combining with the control experiment.