In this work, an upconversion luminescence agent, crystallized Er(3 + ):YAlO(3), was synthesized and then coated by the nano-sized TiO(2) film through sol-gel technique. A novel TiO(2) photocatalyst, Er(3 + ):YAlO(3)/TiO(2), with high activity in visible light was subsequently prepared. The Er(3 + ):YAlO(3) and Er(3 + ):YAlO(3)/TiO(2) were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The photocatalytic activity of Er(3 + ):YAlO(3)/TiO(2) photocatalyst was tested by the degradation of acid red B in aqueous solution as the primary model compound under visible light irradiation. The experimental results proved that the prepared TiO(2)-coated crystallized Er(3 + ):YAlO(3) was able to decompose the acid red B efficiently, and it is promising to use the idea to develop new TiO(2) photocatalyst with high activity for photocatalytic degradation under visible light.