objective to observe the effect of resin filling and metal precrowning on cosmetic restoration of dental caries in children. Methods a total of 80 children with dental caries treated by root canal therapy from January 2022 to December 2022 were 2023. They were randomly divided into control group (N = 40) and observation group (N = 40) . The control group was filled with resin, and the observation group with metal prefabricated crowns, the cosmetic restoration effect, occlusal function, masticatory efficiency, cosmetic satisfaction of teeth, incidence of complications and filling effect were observed and compared between the two groups. Results: the total effective rate (97.50%) in the observation group was higher than that (87.50%) in the control group (P Lt; 0.05) , and the maximum occlusal contact area, occlusal force and masticatory efficiency in the two groups were higher than those before treatment, the satisfaction rate of the observation group (100.00%) was higher than that of the control group (87.50% , P LT; 0.05) , the complication rate of the observation group (7.50%) was lower than that of the control group (25.00% , P LT; 0.05) The scores of restoration retention, marginal cohesion and pulp vitality in both groups were lower than those before treatment, and those in the observation group were lower than those in the control group (P Lt; 0.05) . Conclusion compared with resin filling, metal pre-crowning has a positive effect on the cosmetic effect of root canal therapy in children with dental caries, and can improve the total effective rate of cosmetic restoration and the cosmetic satisfaction of teeth, it can promote the restoration of occlusal function and masticatory function, achieve remarkable filling effect, and has low complication rate, so it is worthy of clinical application.