NOVELTY - A catalyst for reducing hydrogen concentration in fuel battery tail gas comprises a high temperature porous material and a loading active component; its preparation method is a colloid immersion method and comprises (1) preparing colloid platinum by adding formaldehyde solution into hexachloroplatinic acid solution while stirring; adding hydroxide solution; continuously stirring; heating without water; preserving temperature until solution turns to black platinum colloid solution; (2) processing cordierite; and (3) loading process.    USE - The catalyst is useful for reducing hydrogen concentration in fuel battery tail gas (claimed).    ADVANTAGE - The prepared catalyst material active components are mostly on the surface of porous material cordierite and evenly distributed, even the granules are evenly distributed. The process of high temperature hydrogen reduction is not necessary and it is a good method.    DETAILED DESCRIPTION - A catalyst for reducing hydrogen concentration in fuel battery tail gas comprises a high temperature porous material and a loading active component, where the high temperature resistance porous material is cordierite and the loading active component is prepared by loading platinum (Pt) on the high temperature resistance porous material; the preparation method is a colloid immersion method and comprises (1) preparing colloid Pt by adding 4-15 ml of formaldehyde solution into 1 g of hexachloroplatinic acid (H2PtCl6) solution while stirring; stirring for 20-30 minutes and adding 30-60 ml of hydroxide solution; continuously stirring for 30-40 minutes and heating up to 60-90 degrees C without water; preserving the temperature until the solution turns to black platinum colloid solution; (2) processing cordierite by drying cordierite for 6 hours at 120 degrees C and airing it to meet the room temperature; (3) loading process by putting the processed cordierite into a colloid platinum solution of 60-90 degrees C and immersing it for 3-10 minutes; turning the cordierite to a black one and airing it and drying it in a drier on condition of 100-120 degrees C; then getting it out until the temperature is reduced to the room temperature.