This invention provides a preparation method of a catalyst for preferential oxidization of CO in a hydrogen-enriched atmosphere, and a catalyst product obtained from the method and its applications thereof. Particularly, in this invention, a wide-temperature catalyst for preferential oxidization of CO in a hydrogen-enriched atmosphere is obtained by depositing one or more of an iron oxide, cobalt oxide, and nickel oxide as a promoter onto the surface of a supported Pt-group noble metal catalyst precursor via chemical vapor deposition or atomic layer deposition. In the wide-temperature catalyst, the active noble metal component has a content of 0.1 to 10 wt %, and the promoter has a content of 0.1 to 10 wt % in terms of the metal element thereof. In the reaction of preferential oxidation of CO in a hydrogen-enriched atmosphere, the catalyst prepared by this invention can exhibit excellent catalytic performance and can achieve high conversion of CO with high selectivity in a wide temperature range of −80 to 200° C., for example. Also, the catalyst can remain stable for a long time even in a case where steam and CO2 are present in the hydrogen-enriched atmosphere.