Objective To explore the application effect of self-etching adhesive combined with composite resin in the repair of deciduous teeth caries. Methods From September 2018 to March 2022, 72 children with dental caries repair of deciduous teeth in our hospital were selected as the research objects. According to the random number table method, they were divided into control group and observation group, with 36 children in each group. The control group was given routine treatment, and the observation group was given self-etching adhesive combined with composite resin. The clinical efficacy, tooth retention grade rate, pulp sensitivity grade rate, treatment satisfaction and compliance were compared between the two groups. Results The rate of tooth retention grade Ⅲ in the observation group was lower than that in the control group at 1 year after operation, and the difference was statistically significant (P