Objective To explore the effect of metal preformed crown restoration on aesthetic restoration satisfaction in children undergoing primary molar root canal treatment. Methods A total of 40 children who underwent primary molar root canal treatment in the Department of Stomatology, Jingyang Tianchen Dental Clinic from February 2024 to February 2025 were selected, and they were divided into the control group and the observation group according to different restoration materials, with 20 children in each group. The control group was treated with composite resin cavity filling, and the observation group was treated with metal preformed crown restoration. The aesthetic restoration satisfaction, occlusal function, periodontal health and masticatory function were compared between the two groups. Results The maximum bite force and maximum occlusal area in the observation group after treatment were better than those in the control group (P <0.05). The scores of comfort, aesthetics, color and shape in the observation group after treatment were higher than those in the control group (P <0.05). The gingival index and plaque index in the observation group after treatment were smaller than those in the control group (P <0.05). The masticatory function in the observation group after treatment was better than that in the control group (P <0.05). Conclusion The application of metal preformed crown restoration in children's primary molar root canal treatment can improve aesthetic restoration satisfaction, effectively enhance occlusal function, and promote the recovery of periodontal health and masticatory function.