<p>Pollution caused by antibiotics has posed a serious threat to the aquatic environment. In this study, a magnetic Fe₃O₄/CeO₂ composite material was prepared for the efficient removal of oxytetracycline hydrochloride (OTC) from water. The effects of pH, adsorbent dosage, initial OTC concentration, contact time, and temperature on adsorption were systematically investigated. Characterization results confirmed the well-defined structure of the material. Batch adsorption tests achieved a maximum removal rate of 94% at 25℃. The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm model, indicating monolayer adsorption. Thermodynamic analysis revealed a spontaneous and endothermic process. After five adsorption–desorption cycles, the material maintained high removal efficiency, demonstrating excellent regenerability and stability. The adsorption mechanism involved electrostatic attraction, surface complexation, cation–π interactions and hole filling. The results indicate that Fe₃O₄/CeO₂ is an efficient, reusable, and magnetically separable adsorbent and has practical potential for scalable antibiotic removal from wastewater.</p>