Objective To explore the effect of dental plaque indicator technology combined with oral health education on urban and rural children in Honghuagang District. Methods From March to October 2022, 300 students (4-7 years old) in the first grade of kindergarten and primary school in Honghuagang District were randomly divided into the control group and the experimental group, with 150 students in each group. The control group was given oral health education, and the experimental group was given dental plaque indicator technology detection combined with oral health education. The dental plaque index and the incidence of dental caries were compared between the two groups. Results The plaque index of the experimental group was lower than that of the control group at 1, 6 and 12 months, the difference was statistically significant (P <0.05). The incidence of dental caries in the experimental group was lower than that in the control group at 1, 6 and 12 months, the difference was statistically significant (P <0.05). Conclusion Plaque indicator technology combined with oral health education can effectively improve children's oral health and reduce the incidence of dental caries in children in mixed dentition.