NOVELTY - Preparation of homogeneous mesoporous rhodium oxide/aluminum oxide composite catalytic material, comprises: (1) stirring the template agent, aluminum salt in absolute ethyl alcohol, dissolving and then obtaining the uniform aluminum oxide sol; (2) dissolving the rhodium salt into deionized water and preparing into solution, adding to the aluminum oxide sol obtained in step (1); (3) stirring the rhodium oxide/aluminum oxide composite sol obtained in step (2); and (4) calcining the composite sol.    USE - The method is useful for preparing homogeneous mesoporous rhodium oxide/aluminum oxide composite catalytic material, where the material is used for preparing a methane catalytic combustion sensor based on the micro electro mechanical system technology; and for making a detection element, namely a black element of the methane catalytic combustion sensor (all claimed).    ADVANTAGE - The method efficiently produces a composite catalytic material which can be used for preparing the methane catalytic combustion sensor; the beneficial effects are as follows: the composite catalytic material has high specific surface area and loose porous structure, which enhances the catalytic activity of a catalyst; the methane catalytic combustion sensor has the features of the microminiaturization, low power consumption, short response time, high output signal, large signal to noise ratio and convenient carrying and so on.    DETAILED DESCRIPTION - Preparation of homogeneous mesoporous rhodium oxide/aluminum oxide composite catalytic material, comprises: (1) stirring the template agent, aluminum salt in absolute ethyl alcohol in a mol ratio of 1-2 to 10000 to 1000-2000, dissolving and then obtaining the uniform aluminum oxide sol; (2) dissolving the rhodium salt into deionized water and preparing into solution, adding to the aluminum oxide sol obtained in step (1), in the mixture of the solution and aluminum oxide, the mol ratio R of the rhodium and aluminum is more than 0 but less than or equal to 8; ultrasonically scattering to obtain the rhodium oxide/aluminum oxide composite sol; (3) stirring the rhodium oxide/aluminum oxide composite sol obtained in step (2) at room temperature, volatilizing solvent and then obtaining the rhodium oxide/aluminum oxide composite sol; and (4) calcining the composite sol at 400-600 degrees C, removing the template agent, so as to obtain the mesoporous homogeneous rhodium oxide/aluminum oxide composite catalytic material. INDEPENDENT CLAIMS are:    (1) a homogeneous mesoporous rhodium oxide/aluminum oxide composite catalytic material prepared by the method, where in the mixture of the solution and aluminum oxide, the mol ratio R of the rhodium and aluminum is more than 0 but less than or equal to 8; the rhodium oxide/aluminum oxide are uniformly scattered to form the uniform and stable porous loose structure, where the specific surface area of the material is greater than 50 sq.m/g; and    (2) use of the homogeneous mesoporous rhodium oxide/aluminum oxide composite catalytic material in preparing a methane catalytic combustion sensor based on the micro electro mechanical system technology.