Soap is a widely accepted personal cleaning product with strong cleaning ability and low price, which has become a necessity for people's lives. The soap is an alkali salt having a pH of 9.5-10 composed of fat, oil (mainly added with vegetable oil) and salt, and is the simplest anionic surfactant, which is degreased by emulsification of skin surface substances by forming soap salts. Compared with soap, the soap is low in alkali, high in fat and less irritating to the skin than soap.