NOVELTY - Visible light catalyst, i.e., silver-bismuth tungstate loaded on titanium mesh, is claimed. The loading amount is 0.1-2 wt.%.    USE - The visible light catalyst is useful for for catalytic conversion of methane (claimed).    ADVANTAGE - The catalyst has high conversion rate, and is economical.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) preparing the visible light catalyst, comprising (i) mixing bismuth nitrate pentahydrate and sodium tugstate dihydrate in the molar ratio of 2:1, then dissolving in deionized water, stirring the resulting mixed solution at room temperature for 4 hours, to obtain first solution, (ii) adding silver nitrate into the first solution, mechanically stirring at room temperature for 1 hour, to obtain second solution, (iii) transferring the solution into polytetrafluoroethylene lined reactor, adding deionized water, sealing and placing in the oven, carrying out hydrothermal reaction at 180 degrees C for 24 hours, cooling to room temperature, washing the precipitate with deionized water and ethanol, 2-3 times, respectively, oven drying at 80 degrees C for 8 hours, (iv) ultrasonically cleaning and degreasing the titanium mesh, rinsing with deionized water, ultrasonicating for 10 minutes, oven drying at 80 degrees C for 30 minutes, (v) ultrasonically dispersing the resulting silver-bismuth tungstate catalyst in anhydrous ethanol for 30 minutes, then stirring the resulting catalyst in titanium mesh immersed in ethanol solution, evenly pulling the titanium mesh, then drying the titanium mesh at 80 degrees C for 10 minutes, repeating immersing for multiple times, until the load mass ratio is 0.1-2 wt.%; and    (2) use method of visible light catalyst for catalytic conversion of methane, comprising (i) placing the catalyst into a reaction vessel, passing methane-containing gas, so that the methane gas content is 10 vol.% and the relative humidity is 8-10%, (ii) when the methane content and humidity is stable, sealing the reactor, opening the solar simulator intermittent lighting, carrying out visible light catalytic degradation, and recording the methane content and humidity in each procedure, and (iii) when the cumulative sunlight simulator time reaches a certain value at the end of the reaction, recording the methane content and humidity, and calculating methane degradation rate and efficiency.