To investigate the clinical effect of CAD/CAM all-ceramic inlays in the repair of class Ⅱ cavities in posterior teeth. Methods From March to September 2022, 50 patients with classⅡ cavity filling repair of posterior teeth admitted to Yangzhou Stomatological Hospital were selected as the research objects. They were divided into control group and observation group by random number table method, with 25 patients in each group. The control group was treated with ordinary resin filling, and the observation group was treated with CAD/CAM all-ceramic inlay restoration. The aesthetic, functional effects and subjective satisfaction of the two groups were compared. Results The grade A rate of adjacent surface shape, occlusal surface shape, edge coloring and color coordination in the observation group was higher than that in the control group after 1 year of filling repair, and the difference was statistically significant (P <0.05). The A-level rate of adjacent relationship after 6 months of filling repair in the observation group was higher than that in the control group, and the A-level rate of adjacent relationship, edge tightness and no complications after 1 year of filling repair was higher than that in the control group, the difference was statistically significant (P <0.05). The subjective satisfaction score of the observation group was higher than that of the control group after 1 year of filling repair, and the difference was statistically significant (P <0.05). Conclusion CAD/CAM all-ceramic inlay repair for class Ⅱ cavity of posterior teeth can effectively restore the appearance and function of teeth, reduce the incidence of complications and improve patient satisfaction.