The invention relates to a chewable tablet for promoting mouth health and a preparing method thereof, and belongs to the technical field of functional food. The chewable tablet comprises, by weight, 1-10 parts of blueberry extract, 1-10 parts of green tea extract, 0.1-1 part of astragalus polysaccharide, 0.1-1 part of tremella polysaccharide, 1-10 parts of onion powder, 1-10 parts of banana resistant starch, 0.1-3 parts of chitin, 1-20 parts of soybean powder, 0.5-3 parts of casein, 3-15 parts of perillaseed leaf powder, 3-15 parts of lettuce powder, 3-15 parts of cauliflower powder, 3-15 parts of celery powder, 3-15 parts of carrot powder, 0.01-0.05 part of erythritol, 0.01-0.05 part of mannitol, 0.01-0.05 part of xylitol, 1-5 parts of fructo-oligosaccharide, 0.5-1 part of guar gum and 10-20 parts of filling agent. The preparing method of the chewable tablet includes the steps of raw material treating, mixing, pelletizing, drying, packaging and the like. By means of the chewable tablet, the mouth can be completely nursed, various gum diseases can be reduced and prevented, and the mouth health is effectively promoted.