The invention discloses a sweetening agent capable of preventing and treating a deficiency fire toothache. The sweetening agent is prepared from, by weight, 5-7 parts of glycyrrhizin, 2-4 parts of mogroside, 3-5 parts of fructo-oligosaccharide, 2-4 parts of maltitol, 70-80 parts of rebaudioside A, 10-15 parts of stevioside, 6-8 parts of thaumatin and 20-30 parts of a traditional Chinese medicine extract, wherein the traditional Chinese medicine extract is prepared from, by weight, 5-7 parts of rhizoma anemarrhenae, 4-6 parts of radix rehmanniae, 3-5 parts of cortex moutan, 9-12 parts of radix isatidis, 6-8 parts of common yam rhizomes, 3-5 parts of rhizoma polygonati, 4-6 parts of radix rehmanniae preparata, 2-4 parts of lucid ganoderma, 1-3 parts of radix angelica sinensis, 2-4 parts of radix achyranthis bidentatae, 1-3 parts of rhizoma cyperi, 1-2 parts of pericarpium citri reticulatae, 1-2 parts of cortex albiziae and 1-2 parts of radix polygalae. The sweetening agent can clear heat and purge fire, remove toxicity, diminish inflammations and resist bacteria, nourish yin and tonify the liver and the kidney, replenish qi to invigorate the spleen and regulate the body function, has a very good effect on toothache treatment and is free of toxic and side effects.