Magnetic Fe₃O₄@SiO₂–NH₂ nanoparticles were synthesized, characterized and applied as magnetic adsorbing carriers in this paper to separate ovotransferrin (OVT) from chicken egg white. The properties of the particles were characterized, and the results showed that silica shell and terminal amino groups were successfully appended to the Fe₃O₄ core; the mean diameter of the modified particles was about 210 nm and the isoelectric point (pI) was approximately 9.25; in addition the particles displayed desirable magnetic properties, excellent dispersibility and high stability. The particles performed satisfactorily in the separation of OVT and the maximum adsorption loading reached 77.2 mg g⁻¹ in 30 min at 40 °C. Moreover Fe₃O₄@SiO₂–NH₂ nanoparticles were very stable after repeated adsorption–desorption experiments. OVT separated by Fe₃O₄@SiO₂–NH₂ nanoparticles displayed strong ability of binding iron and had a high purity. Besides, the recovery of OVT separated from egg white was calculated to be 84.62%. In addition, the nanoparticles showed desirable repeatability in repeated adsorption–desorption experiments. Hence Fe₃O₄@SiO₂–NH₂ nanoparticles were promising to scale up the separation of OVT from chicken egg white due to the huge advantages of high dispersion, high reactivity, and easy separation.