The invention belongs to the technical field of prevention and controlling of unorganized emission of dust in storing and transporting processes of coal, and discloses a white dust suppressant and a preparation method and application thereof. The white dust suppressant is prepared by the following raw materials in parts by weight: 50-200 parts of polyether diol with molecular weight of 1000, 50-200 parts of polyether diol with molecular weight of 2000, 10-50 parts of epoxy resin E-40 or E-20, 25-100 parts of polyethylene glycol, 50-200 parts of titanium oxide, 25-100 parts of calcium carbonate or argil or diatomite, 5-10 parts of copolymer containing acid group, 2-20 parts of sodium tripolyphosphate or sodium metasilicate, 20-200 parts of propylene glycol methyl ether acetate or 2,2,4-trimethyl-1,3-amyl glycol monoisobutyrate, 5-30 parts of toluene diisocynate, 5-15 parts of N-methyldiethanolamine, 5-15 parts of organic solvent, and 200-500 parts of deionized water.