A method for preparing a zinc sulfate solution impurity removing agent includes the following steps that 2,2-dioctadecyl-1,3-propanediol and carbon disulfide are mixed at low temperature in proportion, sodium hydroxide solid powder is added fractionally in proportion, and 2,2-dioctadecyl-1,3-propylene xanthic acid sodium and water are generated after reaction; the reaction products of 2,2-dioctadecyl-1,3-propylene xanthic acid sodium and water are added into a stainless steel barrel containing a superfluous zinc sulfate solution and stirred, and 2,2-dioctadecyl-1,3-propylene xanthic acid zinc solid and a mixed solution with sodium sulfate and zinc sulfate are generated after reaction; and the solid obtained after centrifugal separation is the zinc sulfate solution impurity removing agent. The impurity removing agent prepared in the invention is low in cost, good in stability, large in capacity, high in applicability and capable of removing various positive ion impurities of copper, cadmium, cobalt, nickel and the like in the zinc sulfate solution at normal temperature.