The excessive consumption and unregulated disposal of antibiotics, including ofloxacin (OFL), levofloxacin (LEV), ciprofloxacin (CIP), norfloxacin (NOR), amoxicillin (AMX), and oxytetracycline (OTC), pose a threat to ecosystems and public health. The unique aspect of our work involves the construction of plasmonic CaIn2S4/Sb2O3/Bi heterojunction via the hydro/solvothermal approach for synergistically reinforcing the catalytic treatment of antibiotics under 150 W LED light. Among all samples, the CaIn2S4/Sb2O3/Bi-10 % hybrid recorded optimum photocatalytic performance against OFL (93.7 %), LEV (97.4 %), CIP (88.9 %), NOR (85.2 %), AMX (81.6 %), and OTC (91.3 %) within 50 min of LED illumination. The CaIn2S4/Sb2O3/Bi-10 % catalysts reflected excellent OFL degradation kinetics of 0.04562 min−1, which is 3.71, 5.01, and 1.83 folds faster than CaIn2S4, Sb2O3, and CaIn2S4/Sb2O3, respectively. Moreover, the mineralization measurements achieved 68.3 % reduction in TOC after 50 min, certifying the satisfactory transformation capabilities of the ternary composite. The photocatalytic mechanism was reasonably proposed based on optical, photoelectrochemical, and XPS characteristics, as well as supported by trapping experiments. It was concluded that the boosted catalytic behavior was linked to synergistic efforts between the S-scheme system and the plasmonic effect of Bi0, promoting the charge separation dynamic, expanding visible-light sensitivity, and optimizing the redox potential. Ultimately, our study offers a new insight on the coupling of the S-scheme system with the plasmonic effect for upgrading the catalytic abilities to address environmental infractions.