Developing electrode materials with a high desalination rate and long life is one of the research hotspots in the field of capacitive deionization (CDI) water treatment technology. CDI electrode (γ-Al₂O₃/ CuO-ACF) was successfully produced by combining laminated CuAl-mixed metal oxide with activated carbon fibers with a one-pot hydrothermal method. The surface morphology, structure and electrode properties of the samples were characterized by SEM, XRD, FTIR and CV. When the voltage increased from 0.8V to 1.6V under NaCl concentration of 500mg/L, the specific electroabsorption capacity, desalination efficiency, current efficiency and energy consumption increased for both electrodes, while those four parameters for γ-Al₂O₃/ CuO-ACF were 23.4%—55.3% higher, 44.8%—82.0% higher, 65.5%—90.0% higher and 15.0%—21.4% lower than those for ACF. Under NaCl concentration of 500mg/L and humic acid concentrations of 5—10mg/L, desalination efficiency for ACF was decreased, but that for γ-Al₂O₃/CuO-ACF was only decreased at humic acid concentration of 10 mg/L. After 15 desalination cycles, the retention rate of desalination efficiency was 96% for NaCl solution system, but that was decreased to 92% with the addition of humic acid. The ion adsorption processes for both cases followed the Langmuir isotherm adsorption kinetic equation, indicating that the salt ions were physically adsorbed on the electrode surface as a single molecular layer. Compared with conventional ACF electrodes, the γ-Al₂O₃/CuO-ACF electrode had excellent recoverability, stability and enhanced electrochemical properties.