NOVELTY - A polynary compound metal oxide catalyst contains carrier, activity component and accessory ingredients. The carrier is a polynary compound metal oxide comprising metal oxides such as alumina, titania, zirconium dioxide and/or ceria, and metal oxides such as calcium oxide, baryta, potassium oxide and/or sodium oxide. The activity component contains powder blue, nickel oxide, molybdenum trioxide and/or tungstic oxide. The accessory ingredient is selected from oxide of cerium, lanthanum, zinc, zirconium, nickel and/or manganese.    USE - Polynary compound metal oxide catalyst is used for promoting transformation reaction of sewage gas.    ADVANTAGE - The polynary compound metal oxide catalyst is manufactured efficiently, and has high activity, stability, anti-hydration property and anti-pulverization property.    DETAILED DESCRIPTION - A polynary compound metal oxide catalyst contains carrier (55-95%), activity component and accessory ingredients (0.1-10%). The carrier is a polynary compound metal oxide comprising metal oxides such as alumina, titania, zirconium dioxide and/or ceria, and metal oxides such as calcium oxide, baryta, potassium oxide and/or sodium oxide. The weight ratio of two metal oxides in the carrier is 2-10. The activity component contains powder blue, nickel oxide (0.1-6%), molybdenum trioxide (2-12%) and/or tungstic oxide (2-12%). The activity component further contains cobalt oxide (0.1-6%). The accessory ingredient is selected from oxide of cerium, lanthanum, zinc, zirconium, nickel and/or manganese. The magnesium and aluminum metal oxide compound in carrier is transformed from anion clay, hydrotalcite or natural anion clay. The metal oxide carrier is hydrate of metal element or soluble salt of metal element. Cobalt nitrate, acetate or soluble salt of cobalt or nickel is used in the reaction. Similarly, ammonium salt of molybdenum and tungsten are used in the reaction. The accessory ingredients are nitrate, acetate or soluble salts of metal elements. The accessory ingredient preferably contains zirconium oxide and ceria in the mol ratio of 1:4-4:1. An INDEPENDENT CLAIM is included for manufacture of the polynary compound metal oxide catalyst.