A Pt thin film catalyst was prepared by a novel green method of micro drop dispersion-oxygen plasma etching (MD-OPE) method with Pt(acac)(2) as starting material and silicon wafer as substrate. The catalytic activity of the film catalyst was evaluated by methanol combustion at room temperature, and its surface properties were characterized by SEM and XPS techniques. The results indicated that Pt(acac)(2) can be decomposed and reduced to PtO and Pt-0 with small size by oxygen plasma, which is the reason for the improved catalytic activity of as-prepared Pt film compared with the Pt film catalysts prepared by the micro drop dispersion (MD) method.