NOVELTY - Noble metal catalyst comprises: a single carrier and many active components, where the carrier is a macroporous gamma -aluminum oxide, whose specific area is larger than 270 m2/g, pore diameter is 5-10 nm, stacking density is 0.7-0.8 g/ml, and purity is more than 99.5%.A noble metal platinum is used as the main active component, and an auxiliary catalyst A and an auxiliary catalyst B are added, where the auxiliary catalyst A is silver, iron, copper and/or nickel, and the auxiliary catalyst B is potassium, sodium and/or lithium.    USE - The catalyst is useful for removing carbon monoxide from synthesis gas (claimed), and also for purifying and removing carbon monoxide in a distributed fuel cell hydrogen-producing system.    ADVANTAGE - The catalyst: has simple production, high catalytic activity, wide temperature operation range, and good selectivity and stability; does not require pre-reduction after the use; and retains the performances even after using for many times.    DETAILED DESCRIPTION - Noble metal catalyst comprises a single carrier and many active components, where the carrier is a macroporous gamma -aluminum oxide, whose specific area is larger than 270 m2/g, pore diameter is 5-10 mm, stacking density is 0.7-0.8 g/ml, and purity is more than 99.5%. A noble metal platinum is used as the main active component, and an auxiliary catalyst A and an auxiliary catalyst B are added, where the auxiliary catalyst A is silver, iron, copper and/or nickel, and the auxiliary catalyst B is potassium, sodium and/or lithium. The content of the noble metal platinum, the auxiliary catalyst A and the auxiliary catalyst B is 0.1-1.5%, 0.05-10% and 1-5% of the total weight of the catalyst, respectively, and the total weight of the catalyst comprises the weight of the carrier. An INDEPENDENT CLAIM is also included for preparing the noble metal catalyst, comprising: (i) immersing the carrier gamma -aluminum oxide into chloroplatinic acid hexahydrate solution (10-100 mg/ml) having the same volume with water absorption of the carrier gamma -aluminum oxide, where the time is 10-30 hours, drying at 100-130 degrees C, and roasting for 2-6 hours at 400-600 degrees C; (ii) immersing the catalyst obtained in the step (i) in nitrate solution of the auxiliary catalyst A, drying at 100-150 degrees C to obtain a constant weight, immersing in nitrate solution of the auxiliary catalyst B, drying at 100-150 degrees C to obtain a constant weight, or immersing the catalyst obtained in the step (i) in nitrate solution of the auxiliary catalyst B, drying at 100-150 degrees C to obtain a constant weight, then immersing in nitrate solution of the auxiliary catalyst A, drying at 100-150 degrees C to obtain a constant weight, and then roasting for 2-6 hours at 400-600 degrees C, where the concentrations of the auxiliary catalyst A and B are 5-300 mg/ml and 50-400 mg/ml, respectively, and the nitrate solutions of the auxiliary catalyst A and B have the same volume; and (iii) reducing the catalyst obtained in the step (ii) for 2-5 hours with hydrogen gas with a concentration of more than 90% to obtain the noble metal catalyst for preferably removing carbon monoxide in reformed gas of natural gas, in which the reducing temperature is 300-400 degrees C.