The invention provides a synergistic coupling treatment method for wastewater. Organic matter is adsorbed by hydroxyl iron oxide and/or oxyferric chloride generated by an electrochemical reaction, synergistic coupling of the hydroxyl iron oxide and/or the oxyferric chloride and ferrous ions is used to catalyze hydrogen peroxide to generate hydroxyl free radicals, so that generation and an effective utilization rate of the hydroxyl free radicals are improved, TOC in the wastewater is removed through deep oxidization, a TOC removing rate can be up to 85% or more, and discharged water can reach surface water discharging standards. The synergistic coupling treatment method for the wastewater provided by the invention is particularly suitable for removal of total organic matter in the wastewater with high salinity and a low organic matter content, has a simple technological process, high efficiency and low costs, can obviously improve treatment quality of the industrial wastewater, and reduce pollution risk on the human water environment.