In this paper, the regulation of oxygen content on the surface of tantalum foil was studied by mechanical polishing and chemical polishing. The results show that it is difficult to obtain relatively clean tantalum surface by mechanical polishing, and tantalum film with low oxygen content can be obtained by argon ion sputtering. Chemical polishing can obtain a relatively clean tantalum surface. The Pd/Ta composite membrane was prepared by electroless plating on the surface of tantalum foil after chemical polishing. In the experiment, by controlling the electroless plating time, a complete and uniform palladium membrane without holes was obtained on the surface of tantalum foil, and the thickness of the palladium film is about 2.8μm.