NOVELTY - Visible mesoporous tungstic oxide-x catalyst comprises oxygen vacancy where x is 0.2-0.5, and the method of preparation includes taking mesoporous silica molecular sieve KIT-6 as hard template, silicotungstic acid or phosphotungstic acid hydrate as the precursor of tungsten trioxide, baking to obtain tungsten trioxide, mesoporous silica molecular sieve KIT-6, and high purity hydrogen gas as a reducing agent, calcining, tungsten trioxide mesoporous silica molecular sieve KIT-6 having oxygen vacancies, adding 10 wt.% aqueous hydrogen fluoride solution.    USE - Used as visible mesoporous tungstic oxide-x catalyst (claimed).    ADVANTAGE - The method of preparation is simple, and is environmentally- friendly.    DETAILED DESCRIPTION - Visible mesoporous Tungstic oxide-x catalyst comprises oxygen vacancy where x is 0.2-0.5, and the method of preparation includes taking mesoporous silica molecular sieve KIT-6 as hard template, silicotungstic acid or phosphotungstic acid hydrate as the precursor of tungsten trioxide, baking in the presence of air at 350-600 degrees C to obtain tungsten trioxide, loading mesoporous silica molecular sieve KIT-6, and high purity hydrogen as a reducing agent, calcining at 450-550 degrees C, tungsten trioxide mesoporous silica molecular sieve KIT-6 having oxygen vacancies, adding 0 wt.% aqueous hydrogen fluoride solution to remove mesoporous silica molecular sieve KIT-6 and obtain the product. An INDEPENDENT CLAIM is also included for preparing Visible mesoporous tungstic oxide-x catalyst comprising (i) adding silicotungstic acid or phosphotungstic acid hydrate in the mass ratio of 1-2:7-12 in anhydrous ethanol, ultrasonicating, mixing for 30 minutes, stirring at the speed of 800 rotation/minute for 1 hour, adding hydrothermal synthesis of mesoporous silica molecular sieve KIT-6, sealing and mixing 1000 rotation/minute for 3 hours, stirring, placing in the water bath at 50-80 degrees C, evaporating anhydrous ethanol to dryness to give a white powder, the hydrothermal synthesis of mesoporous silica molecular sieve KIT-6 includes mesoporous silica molecular sieve KIT-6-35, mesoporous silica molecular sieve KIT-6-100 or mesoporous silica molecular sieve KIT-6-120, dispersing the remaining total mass of silicotungstic acid or phosphotungstic acid hydrate 5-12:1-2 in anhydrous ethanol, ultrasonicating, mixing for 30 minutes, stirring at the speed of 800 rotation/minute for 1 hour, adding the white powder obtained, stirring uniformly, placing in the water bath at 50-80 degrees C, evaporating anhydrous ethanol to dryness, obtaining tungsten trioxide mesoporous silica precursor sieve KIT-6, the mass ratio of mesoporous silica molecular sieve KIT-6, silicotungstic acid and phosphotungstic acid hydrate is 1:3-4, (ii) placing the mesoporous silica precursor sieve KIT-6, the step (i) obtained tungsten trioxide in a corundum crucible, placing the corundum crucible in a muffle furnace under air conditions, adjusting the heating rate at 1 degrees C/minute, and heating at 350 degrees C, annealing for 3 hours, adjusting the heating rate at 1 degrees C/minute, and heating at 600 degrees C, annealing for 4 hours, cooling to room temperature, completing the reaction and obtaining tungsten trioxide mesoporous silica molecular sieve KIT-6, (iii) heating the resultant tungsten trioxide mesoporous silica molecular sieve KIT-6 at heating rate of 1 degrees C/minute with a high purity hydrogen gas atmosphere, calcinating at 450-550 degrees C for 0.5 hours to obtain tungsten trioxide mesoporous silica molecular sieve KIT-6 having oxygen vacancy, (iv) soaking the the resulting tungsten trioxide mesoporous silica molecular sieve KIT-6 having oxygen vacancy in 10 wt.% hydrogen fluoride for 30 minutes, filtering, washing the resulting cake with distilled water until the pH of the effluent is neutral, rinsing with ethanol three times, and drying at 50-80 degrees C for 12-24 hours.