The invention discloses a damp-clearing and toxin-expelling fermentation beverage and a preparing method thereof, and belongs to the field of health-care beverages. The damp-clearing and toxin-expelling fermentation beverage is prepared from, by weight, 5-9 parts of herba portulacae, 4-9 parts of fructus perillae, 3-7 parts of radix angelicae, 5-9 parts of liquorice root, 1-5 parts of fructus canarli, 3-6 parts of fructus gardeniae, 5-11 parts of dried orange peel, 4-9 parts of lotus leaves, 20-50 parts of fructus chaenomelis lagenariae, 30-60 parts of semen coicis, 50-100 parts of semen phaseoli, 20-40 parts of Chinese yam, 100-200 parts of sugarcane, 15-30 parts of amylase and 10-20 parts of lactic acid bacteria. The damp-clearing and toxin-expelling fermentation beverage has the advantages that selected medicines all come from medicine-food-homology medicines, and the fructus chaenomelis lagenariae, Chinese yam, semen coicis and semen phaseoli for fermentation are all common food. Therefore, after being eaten, the damp-clearing and toxin-expelling fermentation beverage cannot cause side effects, and the selected materials can achieve the damp-clearing and toxin-expelling functions through combination.