Abstract: The subject invention relates to two-stage inoculation and two-stage fermentation process which are performed by the inoculation time difference and staged fermentation. In the first stage, yeast, lactic acid bacteria and Acetobacter aceti are inoculated into a fermentation tank to perform primary fermentation to produce primary fermented material. In the second stage, yeast is added into the primary fermented material in a container to perform the secondary fermentation to produce secondary fermented material, and then the secondary fermented material is pasteurized to deactivate yeast, lactic acid bacteria and Acetobacter aceti in the container and stop fermentation reaction. Finally, the secondary fermented material is cooled to ambient temperature to prepare the kombucha fermented beverage preserving active fermentative bacteria and enzyme at ambient temperature. The invention is help to improve the preservation convenience of the kombucha fermented beverage and avoid excessive alcohol concentration.