In order to further improve the properties of the powder, high molecular weight DPMS (dimethyl polysiloxane) is currently used to treat the surface of the powder. The powder has excellent hydrophobicity and high durability, good cosmetic surface, and good adhesion to the skin. , It has a moderate stickiness and good usability. A new powder treatment method has been successfully developed in recent years. The new method is to contact the cyclic methylhydrogen polysiloxane with the powder at a temperature of 100 ℃ or less under normal pressure. Because the surface of the powder has the characteristics of catalytic activity, it can produce a polymerization reaction to form a network polymer, and as a result, an ultra-thin film is formed on the surface of the powder. This film can introduce functional groups through an addition reaction. If the introduced functional group is an alkyl group, a hydrophobic powder will be formed; if it is a hydroxyl group and a polyoxyethylene group, a hydrophilic powder will be formed.