Here, we report a Bi₂S₃ nanorod obtained from the topotactic transformation of single-crystalline Bi₂O₂S and demonstrate its successful performance of enhanced photocatalytic CO₂ reduction. The prepared Bi₂S₃ nanorods exhibit the enlarged band gap with a more negative conduction band position while its single-crystalline characteristic remains unchanged. The accelerated transformation and separation of photogenerated carrier and enhanced adsorption and activation of CO₂ on Bi₂S₃ nanorods is clearly different from that of bulk-Bi₂S₃. As a result, the production of photocatalytic CO₂ reduction to CH₄ on Bi₂S₃ nanorods is 59.9 μmol g^-1h⁻¹ under visible light irradiation and a simulated air atmosphere, which is 2.2 times higher than that of bulk-Bi₂S₃ and remains persistent activity during the repetition experiments. This discovery is believed to pave further exploration for designing unconventional nanostructures and promoting their widely distributed environmental application.