A method for preparing an anti-bacterial anodic oxide film on the surface of aluminum materials, comprising pretreatment, polishing, anodic oxidation, dyeing and sealing, wherein the surface of polished aluminum materials is smooth but has undulating waves and holes; in the dyeing after oxidation, a nano-sized dye is filled in the undulating waves and holes on the surface of aluminum materials, so if nano-silver is uniformly mixed in the dye in the process, the dye on the surface of aluminum materials will contain nano-silver finally and it will protect nano-silver from wearing during use; the dye-filled waves on the surface of aluminum materials are sealed via a sealing process finally, i.e., the dye is sealed in the surface of aluminum materials; at last, the surface of aluminum materials can be turned into desired colored patterns according to actual needs, and the nano-silver provides the anodic oxide film with anti-bacterial effect.