Designing and constructing novel discrete architecture for quantum dots modified ultrathin hollow nanotube Bi2Sn2O7/Bi4O5I2 S-scheme heterojunctions for the first time in this work is an ideal strategy to improve the photocatalytic activity. As expected, the Bi2Sn2O7/Bi4O5I2 heterojunction exhibited outstanding performance of degradation bisphenol A (BPA), the rate constant of Bi2Sn2O7/Bi4O5I2 heterojunction was 1.7 and 41.8 times higher than that of Bi4O5I2 and Bi2Sn2O7, respectively. The promoted activity could be attributed to the spatial separation of photogenerated carriers as well as redox reaction sites due to the discrete structure, and the enhanced charge separation due to the S-scheme mechanism via Bi-O channels as derived from DFT calculations. Furthermore, Bi2Sn2O7/Bi4O5I2 heterojunction exhibited unprecedented ultra-efficient in BPA degradation compared to other published Bi-based catalysts, and excellent performance under actual sunlight contributes to its prospective practical application. This strategy affords a novel approach for fabricating discrete S-scheme heterojunctions photocatalysts with high-efficiency, strong-stable, and sustainable.