A post extraction process for preparing low acyl and clarified gellan gum, comprising the following steps: Deacylation treatment of fermentation broth: The temperature of the fermentation broth is raised up to 80 ∼ 90°C, and an antioxidant is added, and at the same time, a base is added to adjust the pH value to conduct the deacylation; Enzyme treatment of fermentation broth: Into the fermentation broth in Step, different enzymes preparations are added to remove the insoluble impurities and bacterial debris as much as possible; Flocculation of fermentation broth: Into the fermentation broth treated in Step with enzymes, a water-soluble alkali metal is added to flocculate, then the pH value is adjusted into a basic condition, and a solid-liquid separation is conducted so that a large part of water and pigments are removed from the fermentation broth, thereby the raw gellan gum product is obtained; Clarification treatment of gellan gum: The raw gellan gum product obtained in Step is subjected to a clarification treatment and a clarified low acyl gellan gum solution is obtained; Dehydration treatment of the deacylated gellan gum solution Into the gellan gum deacylated and clarified solution obtained in Step, an alkali metal ion is added to form a gel and a solid-liquid separation is conducted; Chelating and decoloration treatment: The gellan gum obtained in Step is cut into grains, most of the divalent or polyvalent cations of the gellan gum are removed via chelating, the gellan gum is slightly pressed to a slightly dried condition and is immersed with a lower alcohol along with agitation; and then a filtration is conducted to reach the effect of complete decoloration; Drying and milling: The gellan gum obtained in Step is pressed to dry and the solid materials are dried and milled, so that a high transparent, low acyl and clarified gellan gum product is obtained. Deacylation treatment of fermentation broth: The temperature of the fermentation broth is raised up to 80 ∼ 90°C, and an antioxidant is added, and at the same time, a base is added to adjust the pH value to conduct the deacylation; Enzyme treatment of fermentation broth: Into the fermentation broth in Step, different enzymes preparations are added to remove the insoluble impurities and bacterial debris as much as possible; Flocculation of fermentation broth: Into the fermentation broth treated in Step with enzymes, a water-soluble alkali metal is added to flocculate, then the pH value is adjusted into a basic condition, and a solid-liquid separation is conducted so that a large part of water and pigments are removed from the fermentation broth, thereby the raw gellan gum product is obtained; Clarification treatment of gellan gum: The raw gellan gum product obtained in Step is subjected to a clarification treatment and a clarified low acyl gellan gum solution is obtained; Dehydration treatment of the deacylated gellan gum solution Into the gellan gum deacylated and clarified solution obtained in Step, an alkali metal ion is added to form a gel and a solid-liquid separation is conducted; Chelating and decoloration treatment: The gellan gum obtained in Step is cut into grains, most of the divalent or polyvalent cations of the gellan gum are removed via chelating, the gellan gum is slightly pressed to a slightly dried condition and is immersed with a lower alcohol along with agitation; and then a filtration is conducted to reach the effect of complete decoloration; Drying and milling: The gellan gum obtained in Step is pressed to dry and the solid materials are dried and milled, so that a high transparent, low acyl and clarified gellan gum product is obtained.