The invention relates to a preparation method of easy-dispersible hexagonal-plate shaped W-type ferrite BaZn2Fe16O27. The preparation method comprises following steps: an original mixed solution of BaCl2.2H2O, ZnCl2, FeCl3.6H2O, and urea is weighed according to a stoichiometric ratio of BaZn2Fe16O27, and is subjected to hydrothermal-assisted homogeneous co-precipitation, pH value of an obtained mixture is adjusted with an alkaline solution to 9 to 11, and the mixture is subjected to aging for 6 to 12h; the mixture is filtered and washed repeatedly until the pH value of an obtained supernatant liquid is 7; an obtained precipitate is dried, a salt is added into the precipitate, and an obtained mixed material is smashed into powder; the obtained powder is subjected to calcining synthesis in a thermal treatment furnace; an obtained product is washed with deionized water, and is dried so as to obtain the easy-dispersible hexagonal-plate shaped W-type ferrite BaZn2Fe16O27. The easy-dispersible hexagonal-plate shaped W-type ferrite BaZn2Fe16O27 possesses a promising potential application prospect in the field of wave-absorbing material. The preparation method is simple in route, high in operability, and low in energy consumption, and possesses high social benefits and economic benefits.