Uranium extraction and recovery play a critical role in guaranteeing the sustainable nuclear energy supply and protecting the environmental safety. The ideal uranium sorbents possess high adsorption capacity, excellent selectivity and reusability, as well as outstanding antimicrobial property, which are greatly desired for the real application of uranium extraction from seawater. To address this challenge, a novel magnetic core-shell adsorbent was designed and fabricated by a facile method. The obtained amidoximed Fe3O4@TiO2 particles (Fe3O4@TiO2-AO) achieved equilibrium in 2 h and the maximum adsorption capacity calculated from Langmuir model is 217.0 mg/g. The adsorption kinetics followed the pseudo-second-order model. Meanwhile, the Fe3O4@TiO2-AO exhibited great selectivity when competitive metal ions and anions coexisted. In addition, the magnetic Fe3O4@TiO2-AO could be conveniently separated and collected by an external magnetic field, the regeneration efficiency maintained at 78.5% even after ten adsorption-desorption cycles. In natural seawater, the uranium uptake reached 87.5 μg/g in 33 days. Furthermore, the TiO2 contained adsorbent showed effective photo induced bactericidal properties against both E. coli and S. aureus. The Fe3O4@TiO2-AO with great U(VI) adsorption performance is highly promising in uranium extraction and reclamation.