The invention discloses a bismuth vanadate chlorine photo-catalyst, a preparation method and an application thereof. A chemical expression formula of the bismuth vanadate chlorine photo-catalyst is Bi9V2O18C1. By use of a high-temperature solid-phase method or a wet-chemical method, the prepared bismuth vanadate chlorine photo-catalyst is an inorganic material containing Bi<3+> bismuth ions; the preparation is convenient and fast, the photo-catalysis reaction can be produced under the visible light, the photo-catalysis efficiency is high, and the physical property and the chemical property of the photo-catalyst are stable. The bismuth vanadate chlorine provided by the invention can be used for degrading organic dye and organic harmful solvent in the wastewater, and can be used as textile finishing agent and used for preparing anti-bacterial and deodorizing functional textiles.