A TiO2-containing composite nano-powder catalyst obtained by combining a titanium-based metal ceramic compound in powder form with a mixing solution containing compound(s) of a platinum group metal and/or a non-noble metal, drying the resulting mixture, and then performing oxidative thermal decomposition on the dried mixture. This catalyst also can be used as a support to further support platinum group metal(s) and/or non-noble metal(s) to obtain another composite nano-powder catalyst. A method for preparing a TiO2-containing composite nano-powder catalyst is also disclosed.