Abstract: Bismuth tungstate (Bi₂WO₆, BWO) as a photocatalytic material has some drawbacks such as a narrow light absorption range and easy recombination of photogenerated carriers, which limit its degradation of pollutants. Using corn stalk powder as the main raw material for carbon quantum dots, the carbon quantum dot/bismuth tungstate (CQDs/BWO) composite material was successfully prepared by the hydrothermal method and applied to the photocatalytic degradation of norfloxacin (NOR). The successful synthesis was confirmed by SEM, XRD, FT-IR, XPS, UV-vis DRS, PL and electrochemical characterization techniques. After the introduction of CQDs, the morphology of BWO is more regular, the crystal structure is not damaged, and the light absorption range of the composite material is broadened. The recombination rate of photogenerated electron-hole pairs is significantly reduced, and the charge transfer efficiency is improved. The influence of different addition amounts of CQDs on the degradation of NOR in the CQDs/BWO system was investigated. Among them, the photocatalytic activity of CQDs/BWO-2 was the best. Within 60 minutes of simulated sunlight irradiation, the degradation rate of 15 mg/L norfloxacin (NOR) reached 97.23%, which was attributed to the formation of a heterojunction between CQDs and BWO promoting the effective separation of charges. After being recycled three times, the removal rate of NOR by the CQDs/BWO system can still reach 95.78%. Free radical capture experiments and ESR indicated that photogenerated holes (h⁺) and superoxide radicals (·O₂⁻) were the main active species, while hydroxyl radicals (·OH) were the secondary active species. The optimization of the above photoelectric performance and the efficient generation of active species jointly achieved the efficient degradation of NOR.