The invention discloses a preparation method of a catalyst with high CO purification performance and the catalyst. The catalyst is used for being coated on the surface of a carrier to prepare an engine tail gas purification catalyst and is prepared by loading noble metal on a carrier material; the noble metal is Ru and one or more of Pt, Pd and Rh, the Ru content is 1g/ft < 3 >-30g/ft < 3 >, and the rest is 5g/ft < 3 >-40g/ft < 3 >; according to the catalyst, a loading material of Ru is adjusted, oxygen deficiency of a Ce-containing material is utilized, the synergistic effect of Ru and the material is increased, migration and sintering of Ru particles under the high-temperature condition are inhibited, and the anti-aging performance of Ru is improved; meanwhile, the roasting temperature of Ru powder is changed, a Ru precursor is firstly converted into Ru oxide, and strong interaction is generated between the Ru oxide and the carrier, so that Ru is in the optimal active valence state, the number of active centers of the whole catalyst coating is increased, and the CO performance and durability of the catalyst are improved; according to the invention, Ru with relatively low price is adopted to replace a part of Pt, Pd and Rh, so that the cost of the catalyst is reduced, and the cost performance of the catalyst is improved.