The invention relates to a preparation method of a platinum-modified titanium dioxide nanowire filter membrane, which comprises the following steps: 1) mixing and stirring a titanium precursor, a high polymer surfactant, an organic acid and an organic solvent, and then dissolving it to a high concentration A hydrothermal reaction is carried out in an alkaline solution, and the reaction product is subjected to an ion exchange reaction in an acidic solution to prepare a titanium-containing nanowire material; 2) adding a platinum precursor, a hole capture agent and water to the titanium-containing nanowire material obtained in step 1) Light deposition is carried out, and then the platinum-modified titanium dioxide nanowire filter membrane is obtained after filtering and washing. The raw material of the present invention is simple and easy to obtain, and the titanium precursor is used as the raw material, and the process is simple through photodeposition of platinum-modified titanium dioxide nanowires, and the obtained platinum-modified titanium dioxide nanowire filter membrane not only has a higher photocatalytic ability It also has a very significant thermal catalytic effect.