<p>Composite hydrogels capable of simultaneous adsorbing organic compounds and metal ions would enhance efficiency and cost-effectiveness in treating effluents discharged from various industrial activities. Nevertheless, complexity of composition in composite hydrogels would pose a challenge in understanding their adsorption behavior comprehensively especially under complicated experimental condition. This study deciphers the relations of experimental condition with adsorption behavior of composite hydrogels comprising of polyethylene glycol, <i>β</i>-cyclodextrin, and montmorillonite. Taking <i>p</i>-hydroxybenzoic acid (PHBA) and lead ion (Pb²⁺) as model analyte, the effects of different parameters including solution pH, temperature, initial concentration, adsorption time, and coexistence of <i>p</i>-hydroxybenzoic acid and Pb²⁺ on adsorption performance were studied in detail. Kinetic models and isothermal models were used to fitting adsorption process. Benefited from synergistic effect among polyethylene glycol, <i>β</i>-cyclodextrin, and montmorillonite, as-prepared composite hydrogels deliver maximum adsorption capacity of 11.96&#xa0;mg/g for PHBA, and 16&#xa0;mg/g for Pb²⁺. Additionally, composite hydrogels exhibit slightly enhanced adsorption performance for Pb²⁺ in PHBA/Pb²⁺ mixing solution owing to the complexation of between Pb²⁺ and hydroxyl group in PHBA and presence of <i>β</i>-CD. This study not only contributes to existing knowledge in the field of adsorption science but highlights the potential of composite hydrogels in efficiently removing aromatic organic compounds and metal ions from aqueous solutions.</p> Graphical abstract <p></p>