The invention provides a method for carrying out bacteria-reducing treatment on precooled chicken carcasses based on slightly acidic electrolyzed water. According to the method, the slightly acidic electrolyzed water is used for acting on the precooled chicken carcasses in a pressure spraying way, and then bacteria-reducing treatment is carried out. After the method is adopted, the initial bacteria carrying amounts of all parts of the surfaces of the chicken carcasses are effectively reduced, the shelf lives of the chicken carcasses are prolonged, and the colors of the surfaces of the chicken carcasses are not influenced. After the carcasses are precooled, a spray washing action way is adopted, so that the disadvantage of a poor bacteria-reducing effect caused by cross contamination and organic matter accumulation in a precooling process of the traditional chicken slaughtering processing production line is made up. The slightly acidic electrolyzed water has the advantages of being efficient, economical, environment-friendly, free from residue and recyclable, thus not influencing the sensory quality of the chicken carcasses, protecting human health and environment, saving water and lowering the costs of related slaughtering production enterprises while playing a good role in bacteria reduction.