Objective To analyze the incidence situation and influencing factors of dental caries incidence in preschool children. Methods From June to December 2021, 300 preschool children aged 3~6 years old from 3 public kindergartens and 2 private kindergartens in Guiyang were selected as the research objects. All children were examined orally, and parents of children were surveyed by questionnaire to observe the situation of children's tooth brushing, eating habits, parents' education level, attention to children's oral health, and whether children were examined regularly. The dental caries status of the subjects was counted, and the influencing factors were analyzed by Logistic regression analysis. Results There was no significant difference in the incidence of dental caries among preschool children of different genders and nationalities (P >0.05). The older the preschool children, the higher the incidence of dental caries (P <0.05). The incidence of dental caries was lower in preschool children with family economic monthly income >10 000 yuan, parents with postgraduate education or above, children eating snacks once a day, paying attention to children's oral health, and regular dental health indicators (P <0.05). Family monthly income, parents' education level, children's snack frequency, children's daily brushing times, whether to pay attention to children's oral health, and whether to carry out regular dental examinations were the main factors affecting the dental caries of preschool children in Guiyang (P <0.05). Conclusion The incidence of dental caries among preschool children in Guiyang city is high, and parents do not pay enough attention to children's oral hygiene and dental health, so it is necessary to strengthen the awareness of caries protection for preschool children to reduce the occurrence of children's dental caries.