Bismuth ferrite (BiFeO3) is a promising material for visible light response photocatalytic applications. In the present work, BiFeO3 particles were synthesized by a polyvinyl alcohol (PVA)-assisted solid state reaction processing. The XRD pattern result indicated that the as-prepared particles are pure BiFeO3 crystalline phase. The microscopy observation demonstrated that the BiFeO3 particle size is from 100 to 200 nm, which is smaller than that of the BiFeO3 prepared without addition of PVA. The HRTEM showed that BiFeO3 particle is polycrystalline and contains many small crystal grains with different orientations. Furthermore, such nanosized and well-dispersed BiFeO3 particles exhibited a much higher photocatalytic activity than the prepared BiFeO3 without addition of PVA for the photodegradation of methyl orange contaminant under visible light irradiation.