Mouldproof piece passes through to absorb the moisture in the air to produce chemical reaction, release ozone, carbon dioxide to kill bacterium, fungus, mould, arrive to resist the action that fungus grows, maintenance leather products. Under the modulating action of the controlled release factor, the mildew proof component can react with the humidity in the environment and release the effective mildew proof factor slowly. The mouldproof factor is volatile and forms a mouldproof atmosphere, which can effectively protect all parts of leather products such as shoes and bags from inside to outside