The invention relates to an ozone catalyst for water treatment, a preparation method thereof and application. The method comprises the steps of loading a zinc oxide nano-film to the surface of a molecular sieve carrier and in-situ growth of cerium oxide nanosheets on the zinc oxide nano-film. Compared with a conventional dipping method for preparation of the ozone catalyst, the method of first generating the zinc oxide nano-film on the surface of the molecular sieve carrier and then performing in-situ growth of the cerium oxide nanosheets on the nano-film not only improves binding force of the catalyst and the carrier, but also greatly increases activity area of the ozone catalyst, so that the decomposition of ozone is accelerated to generate hydroxyl radicals, thereby accelerating the oxidation rate of organic matter in wastewater. The ozone catalyst is simple to prepare and high in catalytic efficiency, does not fall easily and can be reused.