Glycerol hydrogenolysis activity over Cu/Zn–Mg–Al–O catalysts depended strongly on its basicity and hydrogen spillover also enhanced its performance. The calculated TOF of surface Cu atom in Cu0.4/Zn0.6Mg5.0Al2O8.6 reached 26.6h−1 at 200°C in aqueous solution. Display omitted ► The acidity/basicity of Cu/Zn–Mg–Al–O catalysts could be manipulated via adjusting Zn/Mg ratio. ► The conversion of glycerol depended strongly on the basicity of Cu/Zn–Mg–Al–O. ► Hydrogen spillover from Cu to ZnO also enhanced its catalytic performance. ► Cu0.4/Zn0.6Mg5.0Al2O8.6 exhibited the best performance for hydrogenolysis of glycerol at 180°C. ► The TOF of surface Cu atom in Cu0.4/Zn0.6Mg5.0Al2O8.6 reached 26.6h−1 at 200°C. A series of Cu0.4/Zn5.6−xMgxAl2O8.6 catalysts with different Zn/Mg ratios were prepared and used in hydrogenolysis of glycerol in aqueous solution. This reaction proceeded more easily and efficiently over Cu0.4/Zn0.6Mg5.0Al2O8.6 than Cu0.4/Mg5.6Al2O8.6 and Cu0.4/Zn5.6Al2O8.6. The selectivity of 1,2-propanediol is higher than 98.6% in all experiments over Cu0.4/Zn0.6Mg5.0Al2O8.6, and the activity of surface Cu atoms reached 26.6h−1 at 200°C. The structure, morphology, acidity (basicity), and adsorption ability of glycerol/hydrogen for these catalysts were characterized and discussed. It was concluded that the conversion of glycerol depended strongly on the basicity of these Cu-based catalysts and hydrogen spillover also enhanced its performance.