The invention relates to a single-crystal tungsten oxide material, in particular to a preparation method of single-crystal tungsten oxide with high specific surface area. The prior tungsten oxide materials applied to textile printing and dyeing industry and environment protection show low absorbability, unobvious processing effect of dye waste water and other defects. The method comprises the following steps: preparing a propodosoma solution; adding tungstate into water, wherein the mol ratio of the water to the tungstate is from 241 to 483; adjusting pH value; adding acid into the propodosoma solution, mixing the mixed solution, and adjusting the pH value of the solution to from 1 to 2; keeping the solution still for 0.5 to 3 days; after standing still, removing the solution into a polyfluortetraethylene water hot kettle for aging for 6 hours to 8 days at the temperature of 40 DGE.C to 180 DGE.C ; washing the sample obtained in step(4) after centrifugal separation by water for 3 times, and drying the sample put in a constant-temperature drying cabinet for 24 hours at the temperature of 100 DGE.C. The invention has the advantages of simple preparation process, large specific surface area of tungsten oxide, high dye absorbability and favorable processing effect of dye waste water.