A nano-MoS2/TiO2 composite was synthesized in H-2 atmosphere by calcining a MoS3/TiO2 precursor, which was obtained via a quick deposition of MoS3 on anatase nano-TiO2 under a strong acidic condition. The obtained nano-MoS2/TiO2 composite was characterized by X-ray diffraction spectroscopy, Brunauer-Emmett-Teller (BET) surface area, scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive spectrometry, ultraviolet-visible spectroscopy, and Fourier transform infrared spectroscopy. The results show that the composite had a high BET surface area because of its small size and irregularly layered structure. MoS2 in the composite was composed of typical layered structures with thicknesses of 2-8 nm and lengths of 10-40 nm. The composite contained a wide and intensive absorption at 400-700 nm, which is in the visible light region, and presented a positive catalytic effect on removing methyl orange from the aqueous solution. The catalytic activity of the composite was influenced by the initial concentration of methyl orange, the amount of the catalyst, the pH value, and the degradation temperature. In addition, the composite catalyst could be regenerated and repeatedly used via filtration three times. The deactivating catalyst could be reactivated after catalytic reaction by heating at 450 A degrees C for 30 min in H-2.