Xanthan gum, also known as xanthan gum and Hansen gum, is an extracellular acidic heteropolysaccharide produced by fermentation of Xanthomonas. D-glucose, D-mannose and D-glucuronic acid are high molecular weight polysaccharides with a ratio of 2:2:1. The secondary structure of xanthan gum is that the side chain is reversely wound around the backbone of the main chain, and the rod like double helix structure is formed by hydrogen bonding. Xanthan gum is a light yellow to white flowable powder with a slight odor. It is soluble in cold and hot water, neutral, resistant to freezing and thawing, insoluble in ethanol. When it meets with water, it disperses and emulsifies into a stable hydrophilic viscous colloid. Xanthan gum is a kind of biological gum which integrates thickening, suspension, emulsification and stabilization, and has the best performance in the world, so it is widely used in more than ten fields such as food, petroleum, medicine and daily chemical industry. In food: many foods are added xanthan gum as stabilizer, emulsifier, suspending agent, thickener and processing aid. In daily chemical industry: Xanthan gum contains a large number of hydrophilic groups, which is a good surfactant, and has antioxidant, anti-aging and other effects. In medicine: Xanthan gum is a functional component of microcapsule material which is popular in the world and plays an important role in controlling drug release. In petroleum industry, because of its excellent salt resistance and heat resistance, it is widely used in drilling in special environment such as ocean and high salt zone, and can be used as oil displacement agent to reduce dead oil area and improve oil recovery.