The invention discloses a method for preparing child edible mouth care sugar-tablets and belongs to the field of preparation of sugar-tablets. The method disclosed by the invention comprises the following steps: taking smallanthus sonchifolius, chopping the smallanthus sonchifolius, performing soaking and color fixation, and performing drying and grinding after color fixation, thereby obtaining smallanthus sonchifolius powder; mixing the smallanthus sonchifolius powder with corn starch, carry out decoction, and performing cooling and drying to obtain freeze-dried powder after decoction; stirring and mixing the freeze-dried powder, galactooligosaccharide, oligosaccharides, erythritol, xylitol, isomaltitol, malic acid and maltodextrin, thereby obtaining mixed powder; controlling the moisture content of the mixed powder, adding magnesium stearate, and performing tabletting, thereby obtaining the mouth care sugar-tablets. According to the invention, the smallanthus sonchifolius serves as a main raw material of the sugar tablets, an effect of preventing decayed teeth is achieved by utilizing rich fructo-oligosaccharides, and the added galactooligosaccharide, oligosaccharides and the like serve as candy sweetening agents, so that the sugar-tablets disclosed by the invention can meet the requirements of children on desserts, have the effects of resisting bacteria and preventing decayed teeth, are beneficial for human health and small in energy and difficultly add fat.