With the fast development of intensive poultry and aquaculture, the consumption of antibiotics has ever been increasing. Absorbed or metabolized antibiotics usually enter the water environment in the form of active drugs and metabolites, which can enhance the resistance of pathogenic microorganisms and even cause serious water pollution. Considering the bacteriostatic activity of antibiotics, the main biological method used to treat organic waste water has limited efficiency. Herein, we prepared Au/TiO2 for the efficient photocatalytic degradation of lomefloxacin (LOM) antibiotic wastewater. Based on the characteristics of prepared Au/TiO2, the short–wavelength light can be converted into photogenerated carriers with TiO2 support and the long–wavelength light can be converted into heat, likely due to the localized surface plasmon resonance effect of Au, synergistically promoting the LOM degradation. This study not only demonstrates that Au/TiO2 is an efficient photocatalyst for LOM degradation, but also further indicates the effectiveness of photocatalytic technology in the treatment of antibiotic wastewater.