The invention relates to a preparation method for a zirconium-contained rare-earth composite oxide. At a certain ratio, rare earth (cerium, yttrium, praseodymium or terbium) is mixed with zirconium to burden, or rare earth (cerium, yttrium, praseodymium or terbium) and zirconium are mixed with at least one of other metal ions (aluminum, barium, magnesium, strontium, titanium, manganese, ferrum, copper and hafnium) to burden. A magnesium bicarbonate or/ and calcium bicarbonate aqueous solution prepared from raw materials of magnesium or/ and calcium minerals or oxides and hydroxides by at least one working procedure of roasting, digesting, mixing size, carbonizing and the like can serve as a precipitator to carry out precipitation so as to obtain at least one of rare earth and zirconium composite carbonate and subcarbonate, and the at least one of rare earth and zirconium composite carbonate and subcarbonate is further roasted to obtain a zirconium-contained rare-earth composite oxide product. In the preparation method, cheap calcium or/ and magnesium minerals or low-purity oxides and hydroxides can serve as initial raw materials to replace common chemical industry precipitators, such as ammonia water, ammonium bicarbonate, sodium carbonate, sodium hydroxide and the like, substances, such as magnesium, calcium, carbon dioxide and the like can be effectively circulated and utilized so as to greatly lower the production cost of the zirconium-contained rare-earth composite oxide, such as ceria-zirconia, yttrium zirconium, praseodymium zirconium, terbium zirconium and the like. In addition, in the production technology disclosed by the invention, no ammonia nitrogen wastewater, high-salinity wastewater and the like are generated, carbon dioxide greenhouse gas emission amount is reduced, the preparation technology is environmentally-friendly, and environment pollution is avoided.