The invention relates to a preparation method and application of a nanometer ceria-zirconia solid solution-based catalyst for selectively catalytically oxidizing ammonia. The preparation method is characterized in that: a carrier of the prepared catalyst is ceria-zirconia solid solution, and the active ingredients are copper, silver, manganese, iron and the like; and the carrier is prepared by ananionic surfactant method, and the active ingredients are loaded on the ceria-zirconia solid solution by a deposit-precipitation method or impregnation method. The raw material used in the method is not toxic or harmful, and the prepared catalyst has the characteristics of large specific area, mesoporous structure and the like. The catalyst prepared by the method has the advantages of high low-temperature activity, 100 percent of conversion rate when NH3 is at 280 DEG C, good N2 selectivity, wide temperature window, high stability, catalysates of N2 and H2O and no secondary pollution. If the prepared catalyst is pulped and loaded to a honey-comb shaped metal wire mesh or a honey-comb ceramic, the catalyst can be applied to ammonia pollution treatment in tail gas of the practical industry and has wide application prospect.