Abstract: The present invention relates to bismuth-titanium oxide composite nanowires used for photocatalysis and a preparation method, belonging to the field of inorganic nanomaterials. The preparation of the bismuth-titanium oxide composite nanowires is: polyvinylpyrrolidone (PVP) and bismuth nitrate are added to N-N dimethylformamide (DMF), tetrabutyl titanate and acetylacetone are added after magnetic stirring has been performed for a period of time, continual stirring is performed for more than six hours, and a transparent, stable solution is obtained. Electrospinning is performed on the solution in an electrospinning generation device under certain conditions, and the obtained electrospinning precursor nano fibres are air-fired in a muffle furnace to remove organic matter. After being cooled to room temperature, the electrospinning precursor nano fibres are placed in a tube furnace to be reduced and sintered in a hydrogen atmosphere.