The invention provides a method for preparing a montmorillonite-loaded platinum catalyst and belongs to the technical field of fuel batteries. The method comprises the following steps of: exchanging Pt positive ions into a montmorillonite layer of perfluorinated sulfonic acid resin intercalation by an ion exchange method; reducing the Pt positive ions to Pt nano particles by a chemical method; etching montmorillonite into a porous layered structure by using hydrofluoric acid; and introducing carbon powder serving as a conductive agent to form the catalyst with an excellent three-phase interface for catalytic reaction of the fuel batteries. The catalyst prepared by the method has the advantages of high stability and high oxygen reduction activity, can be widely used as the catalyst of proton exchange membrane fuel batteries taking hydrogen and methanol as fuel, has the catalytic activity and the stability which are higher than those of a commercial Pt/C catalyst of Jonhson-Matthey company in Britain, and can replace the same kind of commercial catalyst products.