The invention relates to a solid solution carrier catalyst, and specifically relates to a praseodymium-doped cerium-zirconium carrier catalyst. The carrier catalyst comprises the chemical components of, by weight, 30-50 parts of cerium oxide, 30-50 parts of zirconium oxide, 1-5 parts of praseodymium oxide and 1-5 parts of transition metal. The transition metal is a mixture of vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide and copper oxide. The invention also provides a preparation method of the carrier catalyst. According to the invention, all the raw materials are mixed; a surfactant is added; the pH is regulated to 8-10, and a colloidal precipitate is obtained; and the product is obtained by baking. With the method provided by the invention, a doping defect caused by doping in a cerium-zirconium carrier is overcome, and carried catalyst thermal stability and performance indexes such as aging specific surface area, oxygen storage capacity, and the like are greatly improved. The invention also provides the preparation method of the carrier catalyst. The raw materials are cheap, process is simple, and the method is suitable for large-scale industrialized productions.