A photocatalyst in practical application should integrate together various functions including a visible light response and a feasible and economic recyclability. Herein, a kind of six-layered Aurivillius oxide with a narrow band gap and ferromagnetism (FM) was investigated. Ni-doped Bi₇Fe₃Ti₃O₂₁ (Bi₇Fe_3−xNi_xTi₃O₂₁: BFNTO-x, x = 0.1, 0.4, 0.6, and 1) nanostructures have been synthesized using a hydrothermal method, where Ni substitution for Fe can enhance the FM and specific surface area, as well as improve the photocatalytic activity. The BFNTO-0.6 nanostructure exhibits the maximum saturated magnetization of 2M_s ∼ 3.58 emu g⁻¹ at room temperature, which enables the nanostructure to be fully recyclable simply by using a bar magnet. This research may open a new way for the development of new visible-light-induced photocatalysts because Aurivillius oxide with a layer structure has powerful potential in optimizing its structure and properties by doping.