The invention discloses a method for controlling the by-product of ozone bromate, comprising: preparing cerium oxide-graphene oxide by a hydrothermal method, adding cerium oxide-graphene oxide to an ozone reactor equipped with water to be treated, and utilizing ozone Aeration of the water to be treated with addition of ceria-graphene oxide. The method for controlling the by-product of ozone bromate proposed by the invention can effectively catalyze the oxidation of ozone to degrade organic matter, and effectively inhibit the generation of bromate in the process of catalytic ozonation.