Objective To explore the effect of minimally invasive preparation combined with all-ceramic veneer restoration on aesthetic effect and periodontal health indicators in patients with anterior tooth diastema. Methods A total of 70 patients with anterior tooth diastema (156 affected teeth in total) admitted to our hospital from June 2024 to June 2025 were selected, and they were divided into the control group (35 patients, 77 affected teeth) and the observation group (35 patients, 79 affected teeth) by the random number table method. The control group was treated with conventional preparation combined with all-ceramic veneer restoration, and the observation group was treated with minimally invasive preparation combined with all-ceramic veneer restoration. The aesthetic effect, periodontal health indicators, masticatory function, satisfaction and complication rate were compared between the two groups. Results The scores of marginal adaptation, color matching and appearance morphology in the observation group were higher than those in the control group (P<0.05), while there was no statistically signiffcant difference in translucency score between the two groups (P>0.05). The PLI, BI and PD in the observation group were lower than those in the control group, and the maximum occlusal force and masticatory efffciency were higher than those in the control group (P<0.05). The satisfaction rate of the observation group (97.14%) was higher than that of the control group (82.86%) (P<0.05). There was no significant difference in the incidence of complications between the two groups (P>0.05). Conclusion Minimally invasive preparation combined with all-ceramic veneer restoration for anterior tooth diastema can achieve better aesthetic effect on the basis of reducing tooth tissue damage, which is conducive to maintaining periodontal health and improving masticatory function and patient satisfaction, with high short-term safety.