Multilayer composite material. These include one or more layers of aluminum foil and other materials, such as polyester film, nylon film, polyethylene film and so on. This multi-layer composite structure can provide better moisture-proof, anti-oxidation and fresh-keeping performance, and at the same time, it can also enhance the strength and tear resistance of packaging. In addition, the packaging of military compressed biscuits usually adds moisture-proof agents, antioxidants and other chemicals to further protect food.