layered bimetallic oxides (CuAl LDO) with different molar ratios of Cu: Al were prepared by simple coprecipitation method in this study, which were used to activate persulfate (PMS) to degrade rhodamine B (RhB).The effects of catalyst dosage, PMS dosage, pH value, RhB mass concentration, temperature and inorganic ions on RhB degradation were studied. The properties of the samples were further characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and other technical means.The results showed that under the conditions of adding 30 mg/L CuAl 2:1-LDO and PMS, reaction temperature of 25 ℃, pH=5.61, and RhB mass concentration of 100 mg/L, the RhB degradation rate within 30 min was 97.1%.At the same time, the degradation rate of RhB in CuAl 2:1-LDO/PMS reaction system is more than 90% in the wide range of pH 3.00-11.00, and the degradation rate is still 71% in the fourth cycle experiment.Secondly, the results of electron paramagnetic resonance (EPR) and quenching experiments show that a lot of sulfate radical (SO4-·) and hydroxyl radical (·OH) are produced in CuAl 2:1-LDO/PMS system, in which ·OH plays a leading role in the degradation of RhB, Among them, ·OH plays a leading role in the degradation of RhB, attacking aromatic hydrocarbon ring to decolorize dyes.