Composite buffer film and preparation method thereof

The invention discloses a composite buffer film which sequentially comprises a first buffer rubber layer, a base material layer and a second buffer rubber layer. The first buffer rubber layer and the second buffer rubber layer are prepared from the following raw materials in percentage by mass: 30 to 70 percent of organic silicon pressure-sensitive adhesive, 0.01 to 10 percent of cross-linking agent, 0.01 to 10 percent of catalyst, 0.01 to 10 percent of inhibitor and 20 to 60 percent of solvent; and the base material layer is made of PET (polyethylene terephthalate), silicon rubber or PE (polyethylene). The invention also discloses a preparation method of the composite buffer film. The composite buffer film disclosed by the invention not only has stable holding capacity, but also has a buffer effect higher than that of a single buffer adhesive layer, has the advantages of small falling ball buffer force and unobvious back pressure imprint, and is suitable for being applied to protection of a flexible screen.