A novel visible-light-driven photocatalyst of Mo-doped LiInO2 nanocomposite was successfully synthesized through a sol-gel method. The effect of Mo-doping concentrations on the microstructures and properties of LiInO2 was characterized by X-ray diffraction, scanning electron microscope, X-ray photoelectron spectroscopy, photoluminescence, and ultraviolet-visible absorption spectra. The photocatalytic properties of the as-prepared samples were evaluated by the photocatalytic degradation of methylene blue (MB) dye under visible-light irradiation. The results demonstrated that the photocatalytic activity of 6% Mo-LiInO2 reached to 98.6%, which was much higher than that of the undoped photocatalyst LiInO2 (only 46.8%). The enhanced photocatalytic activity is ascribed to Mo-doping strategy. The holes play an important role in the process of the photodegradation of MB. The superior photocatalytic activity of the as-prepared Mo-LiInO2 nanocomposites suggests a potential application for organic dye degradation of wastewater remediation. This work provides a further understanding on tailoring the band structure of semiconductor photocatalyst for enhancing visible-light absorption and promoting electron-hole separation by Mo-doping strategy.