The invention discloses a sugar-free chewing gum with heatstroke preventing function, and a preparation method thereof. The sugar-free chewing gum is prepared by the following materials, wherein the materials comprise, by weight, 10-20 parts of drug powder, 25-35 parts of a gum matrix, 5-15 parts of xylitol, 35-45 parts of sorbitol, 5-15 parts of mannitol, 5-15 parts of a maltol pulp and 3-5 parts of an aroma agent, and the drug powder is prepared by 15-30 parts of lotus leaves, 10-20 parts of peppermint, 15-30 parts of sweet wormwood herb, 5-10 parts of lotus seed, 5-10 parts of formosan lattuce herb, 5-10 parts of bitter gourd, 5-10 parts of hempleaf negundo chastetree leaves, 5-10 parts of ginseng leaves, 5-10 parts of tamarind pulp and 5-10 parts of mung bean. Compared to the conventional chewing gum, the sugar-free chewing gum of the present invention has the following advantages that: the sugar intake is reduced; the pure traditional Chinese drug preparation with the heatstroke preventing function is introduced, such that the heatstroke patient can conveniently use the product, the side effect caused by the drug can be reduced, and the generation of the heatstroke can be effectively avoided so as to enlarge the product application range and overcome the defects in the prior art.