The invention discloses a bimetal methanation catalyst for the removal of micro carbon monoxide from a hydrogen-rich gas and a preparation method thereof. The bimetal methanation catalyst contains active components, namely nickel oxide and ferric oxide, loaded on an oxide carrier and an assistant, wherein the assistant is at least one element selected from the main group I, the main group II, the subgroup I, the subgroup III, the subgroup VI and the subgroup VIII of the periodic table, and the oxide carrier is alumina, titanium dioxide, zirconium dioxide and silicon dioxide or a mixture thereof. The catalyst of the invention can allow the micro carbon monoxide to be removed from the hydrogen-rich gas at a relatively low temperature and has the advantages of low load, high activity, relatively low cost and wide application prospect.