Objective To explore the application of a digital oral teaching evaluation system in the preparation evaluation of dental restoration teeth. Methods In December 2022, 5 teachers from the Department of Prosthetics at the Fourth Military Medical University Stomatological Hospital and 30 students majoring in Stomatology in 2018 were selected as the research subjects. The digital dental teaching evaluation system (DHC220) was used to train teachers and conduct dental preparation operation assessments. Divide students evenly into Group A and Group B using a random number table method. The teacher first rates the dental preparation operations of Group A students, and then rates Group B students after receiving DHC220 training. Meanwhile, DHC220 automatically rates two groups of students through the system. Apply Friedman test for statistical analysis of teacher ratings and DHC220 ratings, and calculate the intra group correlation coefficient of teacher ratings to evaluate their consistency. Results DHC220 rated Group A students at 65 (25); The scores for Teacher 1 to Teacher 5 were 82 (12), 80 (10), 82 (10), 75 (10), and 83 (8), respectively. The overall difference between the DHC220 score and the teacher score was statistically significant (P<0.001), and only the score of Teacher 4 had no statistically significant difference with the DHC220 score (all P>0.05). The intra group correlation coefficient of teacher ratings was 0.79, indicating good consistency. DHC220's rating for Group B students was 68 (15) points; The scores for Teacher 1 to Teacher 5 were 74 (19), 75 (20), 72 (11), 73 (17), and 74 (13), respectively. The difference between DHC220 scores and teacher scores was still statistically significant (P<0.001), but only the difference between Teacher 1's score and DHC220 scores was statistically significant (P<0.001). There was no statistically significant difference in the comparison of scores between other teachers and DHC220, as well as between teacher scores (all P>0.05). The intra group correlation coefficient of teacher ratings was 0.95, indicating excellent consistency. Conclusions Utilizing a digital teaching assessment system for teacher training can enhance the consistency, accuracy, and objectivity of teachers in evaluating tooth preparations. To a certain extent, it facilitates more effective assessment and feedback in the teaching process.