Stimuli-responsive materials with appealing interactions can serve as key modules for smart devices and have a broad scope of application. In this study, Fe₃O₄@PDA@TiO₂ microspheres with a core–shell structure were assembled. The hollow microspheres have a mesoporous structure and were characterized by SEM, TEM, XRD, Raman, BET, XPS, UV-vis and TGA analyses. Then, a photoresponsive coating with reversibly switchable wettability was prepared by a simple sieve-deposition method using Fe₃O₄@PDA@TiO₂ powder. In addition, the Fe₃O₄@PDA@TiO₂ coated fiber textile was obtained by a dipping method and was used for oil–water separation due to its underwater superoleophobicity. Finally, it was found that this material with its hollow and mesoporous structure can be used for dye adsorption, while the anatase TiO₂ ingredient shows good photocatalysis performance.