Objective To analyze the effect of layered composite resin technique on space closure efficacy and aesthetic effect in patients with periodontitis and anterior diastema. Methods A total of 80 patients with periodontitis and anterior diastema treated in the Department of Stomatology, the First People's Hospital of Changzhou from February 2022 to June 2025 were selected as the research subjects. According to the random number table method, they were divided into the control group and the observation group, with 40 patients in each group. The control group was treated with direct adhesive composite resin restoration technique, and the observation group was treated with layered composite resin technique. The space closure efficacy, dental function, aesthetic effect and emotional status were compared between the two groups. Results The effective rate of space closure in the observation group (97.50%) was higher than that in the control group (80.00%) (P <0.05). At 6 months after restoration, the masticatory efficiency and occlusal force in the observation group were higher than those in the control group (P <0.05). At 6 months after restoration, all aesthetic effect scores of the observation group were better than those of the control group (P <0.05). At 6 months after restoration, the scores of SAS and SDS in the observation group were lower than those in the control group (P <0.05). Conclusion Layered composite resin technique can improve the space closure efficacy for patients with periodontitis and anterior diastema, enhance dental function and aesthetic performance, and relieve their negative emotions.