Unveiling the charge separation and transfer pathways and exploring low‐cost and durable heterojunction photocatalysts are still two key challenges in achieving high‐efficient solar fuel generation from low‐concentration carbon dioxide. Herein, the layered In 2 S 3 ‐modified Nb 2 O 5 hybrid nanofiber photocatalysts with core–shell structures for efficient low‐concentration CO 2 hydrogenation are constructed. The as‐prepared binary S‐scheme photocatalysts show excellent CO generation of 60.36 μmol g −1 h −1 , which is 5.6 and 3.8 times higher than that of Nb 2 O 5 and In 2 S 3 , which not only exhibits the CO generation in low‐concentration CO 2 but also is superior to most photocatalysts without sacrificial agents or cocatalysts. In situ illuminated X‐ray photoelectron spectroscopy analysis indicates the S‐scheme charge transfer pathways formed due to the unmatched Fermi level, creating an internal electric field at the core/shell interface, driving the separation of the photoexcited charge carriers. This work will provide a promising strategy for constructing nanofiber‐based heterojunction photocatalysts for efficient low‐concentration CO 2 hydrogenation reactions.