The invention discloses a chewable tablet for preventing and treating dental ulcer and a preparation method thereof. The chewable tablet disclosed by the invention comprises the following raw materials: radix bupleuri, rhizoma anemarrhenae, prepared rheum officinale, radix tinosporae, heracleum rapula Franch, nidus vespae, rhizoma bolbostemmae, fingered citron sheets, fructus akebiae, salvia chinensis, oldenlandia diffusa, dichrocephala auriculata, Chinese photinia leaves, L-arabinose, gum base, a stabilizer, pigments and a gloss agent. According to the chewable tablet disclosed by the invention, medicines in the chewable tablet are combined for synergistic interaction to achieve the functions of replenishing the vital essence, removing heat, tonifying spleen and tonifying qi and also has detoxifying and astringency functions. The chewable tablet is suitable for various dental ulcers. Compared with the prior art, the chewable tablet disclosed by the invention integrates the effects of resisting bacteria, resisting viruses, resisting infection and improving the immunity and is high in effective rate.