The invention provides a cleaning catalyst for automobile exhaust and a preparation method of a cleaning catalyst carrier. The catalyst comprises a carrier, an aid coating coated on the carrier, and an active ingredient loaded on the carrier coating, wherein the active ingredient is a mixed metallic oxide of yttrium, lanthanum, cerium, zirconium, manganese, copper and nickel; the carrier contains alumina and rare-earth lanthanum cerium oxide; and the aid coating is one or several oxides containing lanthanum, cerium, yttrium and zirconium. The preparation method of the carrier comprises the following steps of: hydrolyzing anhydrous aluminum chloride to prepare high-purity alumina, and preparing a saturated solution of lanthanum and cerium nitrate; adding the saturated solution into alumina, stirring, drying, grinding, mixing with graphite and polyethylene glycol, performing mold pressing and roasting. The catalyst has the characteristics that platinum, rhodium and other precious metals are not used, the cost is low, the activity is high, the heat, ageing and oxidization resistance capabilities are high, and the preparation process is simple.