The qualified glucose enters the fermentation system to maintain a certain fermentation time to get the qualified fermentation mash. After heating, the bacteria in the fermentation mash is inactivated, then filter the mycelium protein and insoluble particles in the fermentation mash, it enters the concentration system for the concentration. A certain amount of solvent is added to the concentrated fermentation mash and stirred to make it fully mixed, so that the fiber is precipitated completely. After separation and precipitation, the product is got. After secondary washing, separation, pressing and dehydration treatment, part of the pigment, impurities and water are removed, and the product is dried by the dryer to obtain the qualified gellan gum product.