NOVELTY - Preparation of perovskite type lanthanum calcium cobalt oxide/silver composite powder oxygen reduction catalyst comprises dissolving calcium nitrate tetrahydrate, cobalt nitrate hexahydrate, and lanthanum nitrate hexahydrate in distilled water, regulating pH, adding citric acid, and hydrolyzing to prepare sol; drying, aging, heating, naturally cooling, finely grinding, roasting, and keeping warm to prepare lanthanum calcium cobalt oxide powder; adding into ammoniated silver complex solution; dropwise adding reducing agent; and filtering, cleaning, heating, and drying by distillation.    USE - Preparation of catalyst (C1) (claimed) used in low-temperature alkaline fuel cell or metal-air battery.    ADVANTAGE - Compared with the prior art perovskite type oxide catalyst, the catalyst (C1) has increased conductivity and improved catalytic activity. Compared with pure Ag catalyst, the catalyst (C1) has greatly reduced cost.    DETAILED DESCRIPTION - Preparation of perovskite type lanthanum calcium cobalt oxide (LaxCa1-xCoO3)/silver (Ag) composite powder oxygen reduction catalyst (C1) comprises:    (A) weighing calcium nitrate tetrahydrate (Ca(NO3)2.4H2O), cobalt nitrate hexahydrate (Co(NO3)2.6H2O), and lanthanum nitrate hexahydrate (La(NO3)2.6H2O); dissolving in distilled water; taking a small quantity of the solution; using nitric acid and ammonia water to regulate the pH at 0.9-3.0; adding 1-5 wt.% citric acid; and hydrolyzing the solution at constant temperature of 40-95 degrees C to prepare sol;    (B) drying the moisture of sol by distillation to obtain pink gel; and aging for 10-72 hours under room temperature;    (C) placing aged gel into a muffle furnace; heating up to 500 degrees C from room temperature; keeping warm for 2-8 hours to resolve the residual nitrate radical in the gel; and naturally cooling to obtain black powder;    (D) transferring the black powder into a mortar and finely grinding; placing into a corundum crucible; roasting by an electric furnace at 700-900 degrees C to transform it into perovskite structure phase under high temperature; and keeping warm for 6-24 hours to prepare LaxCa1-xCoO3 powder; and    (E) preparing 1-5 M AgNO3 solution; adding ammonia water into the solution to generate sediments; continuously adding ammonia water to make the sediments disappear and produce ammoniated silver complex; adding prepared LaxCa1-xCoO3 powder into ammoniated silver complex solution, where mass ratio of perovskite oxide and Ag is 0.90-0.999:0.10-0.001; dropwise adding reducing agent of hydrazine hydrate, formaldehyde, or solution of sodium potassium tartrate tetrahydrate; stirring while dropwise adding, where quantity of reducing agent is 1.2-2 times the desired quantity of reducing silver ion, and temperature is constant at 20-60 degrees C; and filtering, cleaning, heating, and drying by distillation to prepare LaxCa1-xCoO3/Ag composite powder with silver being deposited on the surface of perovskite type oxide.    An INDEPENDENT CLAIM is included for catalyst (C1).