Objective To explore the effect of nano-composite resin in the restoration of anterior tooth defect, and analyze its inffuence on patients' aesthetic effect and occlusal function. Methods A total of 120 patients with anterior tooth defect who were treated in the Department of Stomatology of our hospital from June 2021 to May 2023 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 60 patients in each group. The control group was treated with traditional microfflled composite resin, and the observation group was treated with nano-composite resin. The aesthetic effect, occlusal function, complication rate and satisfaction were compared between the two groups. Results The scores of color matching, morphological naturalness and marginal adaptation in the observation group were better than those in the control group (P<0.05). After restoration, the maximum occlusal force and anterior guidance inclination of the observation group were higher than those of the control group (P<0.05). The incidence of complications in the observation group was 5.00%, which was lower than 18.33% in the control group (P<0.05). The satisfaction rate in the observation group was 96.67%, which was higher than 81.67% in the control group (P<0.05). Conclusion The application of nano-composite resin in the restoration of anterior tooth defect has excellent aesthetic effect. It can effectively restore patients' anterior tooth occlusal function, with a lower incidence of complications and higher satisfaction.