Magnetic Ni0.3Mg0.3Zn0.4Fe₂O₄ nanoparticles were synthesized by the absolute alcohol combustion method. The morphology, microstructure, and composition of as-prepared Ni0.3Mg0.3Zn0.4Fe₂O₄ nanoparticles were characterized by several techniques: the vibrating sample magnetometer (VSM), the scanning electron microscopy (SEM), the X-ray diffraction (XRD), and the energy dispersive spectroscopy (EDS). The experimental results showed that the calcination temperature and the solvent volume were the crucial factors for the synthesis of the magnetic Ni0.3Mg0.3Zn0.4Fe₂O₄ nanoparticles. The adsorption performance of Ni0.3Mg0.3Zn0.4Fe₂O₄ nanoparticles for congo red (CR) was investigated. The model of pseudo-second-order kinetic was optimal matching for obtaining the parameters of adsorption CR in the initial range of 100-400 mg/L-1, while, the isotherm data of CR onto Ni0.3Mg0.3Zn0.4Fe₂O₄ nanoparticles could conform to the Temkin model owing to the values of the square deviations, which revealed that the adsorption of CR onto Ni0.3Mg0.3Zn0.4Fe₂O₄ nanoparticles at room temperature was the monolayer and multilayer adsorption mechanism.