It is an urgent matter to eliminate antibiotics in waste water, due to the rapid emergence of antibiotic resistance. The search for low cost, high activity and stable novel photocatalysts has attracted great interest. Herein, we demonstrated the rational construction of CNT/LaVO4 nanostructures for efficient antibiotic photodegradation by a one-step hydrothermal method. The phase structures, chemical compositions, morphologies, and optical properties of the prepared samples were investigated via various characterization techniques. The optimized CNT/LaVO4 nanostructures exhibited efficient photodegradation activity with remarkable stability. The 0.1% CNT/LaVO4 showed the highest tetracycline degradation rate, which is 2 times that of pure LaVO4. Photoluminescence (PL), transient photocurrent response and electrochemical impedance spectroscopy (EIS) together verified that this design successfully expedites the separation and transfer of photogenerated charge carriers. Subsequently, by the electron spin resonance (ESR) spin-trap technique, free radical trapping experiments and mass spectrometry analysis (MS), the active species, intermediate product, photodegradation pathway and reaction mechanism during the photocatalytic process were identified. The antibacterial results showed that the degrading products have lower toxicity. The CNT/LaVO4 composite is a potential photocatalyst for improving the water quality.