The invention relates to the field of salt-containing wastewater treatment, in particular to a method for treating salt-containing wastewater. The method comprises the steps that the salt-containing wastewater is sent to a pretreatment unit for pretreatment and pretreated effluent is obtained; sulfates are introduced into the pretreated effluent and a mixture is mixed with divalent cation-rich concentrated water added with a deactivating agent to be sent into a crystallizer for crystallization treatment to obtain a calcium sulfate crystal salt and crystallized effluent; and a scale inhibitor is introduced into the crystallized effluent and then a mixture is sent into a salt separation unit for salt separation treatment to obtain divalent cation-rich concentrated water and divalent cation lacking produced water, and the deactivating agent is one or more of hypochlorite, chlorine, chlorine dioxide and a peroxide. According to the method for treating the salt-containing wastewater, a method of oxidative deactivation is adopted, the scale inhibitor is quickly and efficiently deactivated, COD after membrane concentration is simultaneously treated, and the reuse water does not pollute amembrane after treatment; and on the other hand, the quality of salts can be significantly improved by an oxidation treatment method.