To investigate the effect of preformed metal crowns restoration of deciduous teeth on occlusal function in children with high-risk caries. Methods A total of 70 children with high-risk caries admitted to Yangzhou Stomatological Hospital from January 2018 to June 2023 were selected as the research objects. They were divided into control group and study group according to different treatment schemes, with 35 children in each group. The control group was treated with solidified resin filling repair, and the study group was treated with preformed metal crowns restoration of deciduous teeth. The repair effect, occlusal function and masticatory efficiency, periodontal tissue, complication rate and repair satisfaction were compared between the two groups. Results The success rate of repair in the study group was 94.29%, which was higher than 77.14% in the control group (P <0.05). After treatment, the occlusal function and masticatory efficiency of the two groups were better than those before treatment, and those in the study group were better than those in the control group (P <0.05). After treatment, the levels of local gingival crevicular fluid and alkaline phospholipase in the two groups were higher than those before treatment, but those in the study group were lower than those in the control group (P <0.05). The incidence of complications in the study group was 5.71%, which was lower than 22.86% in the control group (P <0.05). The repair satisfaction of the study group was 94.29 %, which was higher than 77.14 % of the control group (P <0.05). Conclusion The application of preformed metal crowns restoration of deciduous teeth can effectively improve occlusal function and periodontal tissue in children with high-risk caries, improve their masticatory efficiency and repair effect, reduce the incidence of complications, and have high repair satisfaction.