MoS₂ nanoflowers are favored for their potential in the production of elemental sulfur due to abundant surface area and good catalytic performance for reducing SO₂. A novel synthetic strategy of porous Al₂O₃ supported on the MoS₂ with nanoflower structure was proposed. The effects of preparation concentration, calcination atmosphere, and Al₂O₃ contents on the growth of catalysts with nanoflower structure were systematically studied via X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and Brunauer–Emmett–Teller (BET). The surface area was increased to 295.502 m²/g and the amount of Lewis acid on the surface of the Al₂O₃/MoS₂ catalyst was increased by adjusting the ratio of Al/Mo. The porous and nanoflower structures of Al₂O₃/MoS₂ catalysts promoted the sulfur selectivity without inhibiting the catalytic performance of MoS₂. The conversion of SO₂ and the selectivity of sulfur were 100% and 92% after 100 h life evaluation.