Objective To explore the Effect of minimally invasive crown lengthening combined with nano resin restoration for subgingival wedge-shaped defect. Methods A total of 70 patients with subgingival wedge-shaped defect admitted to Beilin Herong Dental Clinic in Xi'an from January 2020 to December 2021 were randomly divided into study group and control group, with 35 patients in each group. The control group was given conventional crown lengthening combined with nano resin repair, and the study group was given minimally invasive crown lengthening combined with nano resin restoration. The repair success rate, periodontal related index changes and postoperative pain degree were compared between the two groups. Results The repair success rate of the study group was 94.29%, which was higher than 74.29% of the control group (P0.05). The VAS scores of the study group were lower than those of the control group on the 1st, 3rd and 5th day after operation (P