TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The metal in the noble metal salt consists of gold, platinum and/or palladium. The solvent for the noble metal salt solution can also be water. The concentration of the noble metal salt solution is 0.05-0.10 mole/L (preferably 0.07 mole/L).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The titanate solution comprises n-ethyl ester titanate, normal isopropyl nitrate titanate, and/or n-butyl ester titanate; and a solvent consisting of a mixed solution of ethyl alcohol and acetic acid. The volume ratio of ethyl alcohol to acetic acid in the mixed solution of ethyl alcohol and acetic acid is 1:1. The alcohol used in step (2) consists of 2-10C monohydric or divalent alcohol, preferably ethyl alcohol, propyl alcohol, butyl alcohol, ethanediol or glycerol. The solvent for the noble metal salt solution can be 2-10C monohydric or divalent alcohol, preferably ethyl alcohol, propyl alcohol, butyl alcohol, ethanediol or glycerol.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polyvinylpyrrolidone solution comprises polyvinylpyrrolidone having a number-average molar mass of 1300000, and a solvent consisting of ethyl alcohol. Preferred Method: In step (1), the mass ratio of titanate to polyvinylpyrrolidone is (2:1)-(5:1) (preferably 4:1); the electrostatic spinning process is performed with a flow speed of the electrostatic spinning original solution of 4-20 mL/hour; and the roasting process is performed at 400-500 degrees C (preferably 500 degrees C) for 3-8 hours (preferably 4 hours). In step (2), the dosage ratio of the anatase type titanium dioxide (TiO2) nano fiber, the alcohol, and the noble metal salt solution is (0.2-2 g):(20-300 mL):(2-20 mL) (preferably 0.2 g:30 mL:3 mL); the batch-type microwave heating process is performed for 2-60 minutes at a microwave frequency of 2000-3000 MHz (preferably 2450 MHz) and a microwave power of 80-1000 W (preferably 650-800 W); washing process is performed using deionized water and/or ethyl alcohol; and drying process is performed at 80-200 degrees C (preferably 80 degrees C) for 1-2 hours (preferably 2 hours).