As a persistent antibiotic, tetracycline is widely used in medical and livestock farming fields. However, the longterm accumulation effect of tetracycline has a significant impact on the ecosystem. In this research, we integrated the processes of adsorption-photocatalytic degradation for organic pollutants by combining Sichuan Pepper shell biochar adsorption, TiO2 Nanorods photocatalytic oxidation, and Au nanoparticles Localized Surface Plasmon Resonance. The findings demonstrated that the specific surface area of Au nanoparticles/TiO2 nanorods/biochar has increased by 1287.6 m2/g compared to TiO2. Furthermore, when TiO2 is compounded with biochar, its particle size reduces by approximately half and forms C-Ti and N-Ti bonds. The composite catalyst exhibited the highest removal rate for tetracycline, nearly four times that of commercial TiO2 (P25), showing excellent application prospects. The enhanced composite structure improved its ability to capture sunlight, leading to more effective photocatalysis. This research explains the composite and synergistic mechanism of biochar, TiO2 nanorods, and Au nanoparticles, which could guide the removal of organic pollutants.