Abstract: Coal gangue is rich in SiO₂ and Al₂O₃, and can be used as raw material for zeolite molecular sieve. A molecular sieve was prepared by coal gangue from Zaozhuang Mining Group, through the process of low−temperature oxidation, acid leaching, high−temperature calcination, activated by alkali melting, and further hydrothermal reaction. The crystal structure, morphology, and skeleton structure of the product were characterized by X−ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT−IR) respectively. The results showed that the product was a 4A molecular sieve with good morphology and high crystallinity. The prepared molecular sieve was used for the adsorption of Cu²⁺ in aqueous solution, and the effects of molecular sieve dosage, solution pH value, adsorption time, and temperature on the adsorption effect were investigated. Adsorption experiments showed that its adsorption rate for Cu²⁺ reached 89.2% in the acid wastewater containing 0.01 mol/L of copper, when the dosage was 6.0 g/L, the pH value was 5.0, the adsorption time was 180 min, and the adsorption temperature was 40 ℃. The adsorption kinetics analysis showed that the adsorption process conformed to quasi second−order kinetic equation, and chemical adsorption played a dominant role in the adsorption process.