Abstract: The adsorption characteristics of heavy metal ions in wastewater were investigated by using red mud-based adsorbent. The adsorption mechanism of red mud-based adsorbent was investigated by means of adsorption kinetic model, adsorption isotherm, FTIR and XRD with Cu²⁺and Zn²⁺ in acidic wastewater as the target. The results showed that the adsorption process of heavy metal ions Cu²⁺ and Zn²⁺ by the red mud-based adsorbent belonged to monomolecular layer adsorption, and the maximum adsorption amounts of Cu²⁺ and Zn²⁺ by Langmuir adsorption isotherms were 33.12 mg/g and 129.88 mg/g, respectively, which were in accordance with the quasi-secondary kinetic model. The Si-O-Si in the red mud-based adsorbent interacted with Cu²⁺ and Zn²⁺ and the adsorption process was chemisorption. This study provides a new way for the recycling of solid waste red mud from aluminum industry.