The invention relates to medicine field, and particularly relates to an angiotensin II receptor antagonist valsartan dispersible tablet and a preparation method thereof. The prescription of the product comprises pharmaceutical adjuvants acceptable in pharmacy like valsartan bulk drug, a filler, a disintegrant, an adhesive, flow aid, a lubricant, and corrigent, and the dispersible tablet is prepared by a wet granulation method. The valsartan bulk drug needs to be micronized, and the diameter 90 is less than 75mu m, preferably, the diameter 90 is less than 10mu m. The size distribution of the valsartan bulk drug directly affects the dispersibility of the dispersible tablet. The valsartan has polymorphy, different crystal forms of valsartan have different size distribution, and the dispersibility of the valsartan dispersible tablet is more different. The size distribution of the valsartan bulk drug is controlled by virtue of the micronization technology, the diameter 90 is less than 75mu m, preferably, when the diameter 90 is less than 10mu m, the difference of size distribution of different crystal forms of valsartan bulk drug is eliminated, the dispersibility of the valsartan dispersible tablet is improved obviously, the drug dissolution rate of the valsartan dispersible tablet is improved, and the product quality is controllable and is improved remarkably.