Guar gum is a macromolecular natural hydrophilic colloid, which belongs to natural galactomannan, one of the quality improvers and a natural thickening agent. The appearance is from white to yellowish free-flowing powder, can dissolve in cold or hot water, and form a gelatinous substance after water, to achieve rapid thickening effect. It is mainly divided into food grade and industrial grade (those used in oil fields belong to industrial grade).