Sodium pyrophosphate is an inorganic compound with the chemical formula Na4P2O7, is a white crystalline powder, which is easy to absorb water and deliquescence in air, soluble in water, insoluble in ethanol and other organic solvents. With Cu2+、Fe3+、Mn2+The isometal ion complexation ability is strong, and the aqueous solution is stable below 70 °C, and it is hydrolyzed into disodium hydrogen phosphate when boiled. The electroplating industry is used to prepare electroplating solutions, which can form complexes with iron. The wool textile industry is used as a wool degreaser and bleaching agent. The paper industry is used for the bleaching of paper and plant fibers. The printing and dyeing industry is used as an auxiliary agent in printing and dyeing and fine bleaching. It is used as a toothpaste additive in the daily chemical industry, which can form colloids with calcium dicalcium phosphate and play a stabilizing role, and can also be used in the synthesis of detergents and the production of products such as shampoo. As a water softener in water treatment. Used as a rust remover in machining. Used as a dispersant and emulsifier in chemical production. It can also be used as a water treatment agent, oil drilling, etc., and as a quality improver, emulsifier, buffer, chelating agent, etc. in the food industry.