To investigate the clinical application effect of rubber barrier four-hand operation in composite resin filling of lower right first molar. Methods A total of 120 patients who received composite resin filling treatment for the lower right first molar at the Stomatology Center of China-Japan Friendship Hospital from January 2022 to January 2023 were selected as study subjects and randomly divided into experimental group and control group, with 60 patients in each group. The experimental group received rubber barrier four-hand operation nursing, while the control group received non-rubber barrier four-hand operation nursing. The nursing effect, cognition degree of rubber barrier use, nursing satisfaction and complications were compared between the two groups. Results The nursing effect of the experimental group was better than that of the control group (P <0.05). The awareness rate of rubber barrier use in the experimental group was 21.67%, which was slightly higher than 13.00% in the control group, but the difference was not statistically significant (P >0.05). The satisfaction rates of doctors and patients in the experimental group were 91.70% and 88.33%, respectively, which were higher than 75.00% and 66.67% in the control group (P <0.05). The incidence of complications in the experimental group was 3.33%, which was lower than 15.00% in the control group (P <0.05). Conclusion The application effect of rubber barrier four-handed operation in composite resin filling of lower right first molar is accurate, and the satisfaction of doctors and patients with nursing has also been greatly improved. Meanwhile, the overall awareness rate of patients on the use of rubber barrier is low.