Sodium citrate is nontoxic, pH adjustable and stable, so it can be used in food industry. Sodium citrate is used as food additive, and its demand is the largest. It is mainly used as seasoning agent, buffer, emulsifier, expander, stabilizer and preservative; In addition, sodium citrate is compatible with citric acid and can be used as gelling agent, nutritional supplement and flavor agent for jam, jelly, juice, beverage, cold drink, dairy products and pastry. When fresh blood is taken in clinic, adding some sterilized sodium citrate can prevent blood coagulation. It is precisely by taking advantage of the characteristic that citrate and calcium ion can form a soluble complex. It is used in the field of medicine for anticoagulants in vitro and anticoagulants, expectorants and diuretics in blood transfusion. In electroplating industry for cyanide free industry, photographic industry for developer.