A method and device for removing chloride ions in desulfurized wastewater by electrochemical coupling in which the device comprises: an electrolyte tank having a top and a bottom wherein the tank is used as a separator in a separation process and as an electrode regenerator in an electrode regeneration process; two electrodes comprising a hydrogen evolution electrocatalysis function electrode and an electrochemically switched ion exchange (ESIX) function electrode respectively, wherein the electrodes are connected with each other by a wire; two DC circuits having opposite electric field directions and used alternately in the separation process and the electrode regeneration process respectively; the bottom of the electrolyte tank is provided with a purified high-concentration chloride ion wastewater inlet and a flocculation product outlet; the top of the tank is provided with a dechlorination treatment water outlet and a hydrogen collecting port; and, in the electrode regeneration process, the electrolyte tank is connected to an electrode regeneration liquid storage tank through a pump and a pipeline.