Objective: To explore the effects of local injection of epinephrine and lidocaine on postoperative pain and bleeding in children undergoing tonsillectomy. Methods: Sixty-eight children who underwent a tonsillectomy in our hospital from March 2019 to October 2020 were selected. The children were randomly divided into two groups of 34 cases each. The observation group received local anesthetic injections of lidocaine and the control group received local anesthetic injections of epinephrine. The postoperative pain, operation time, blood pressure changes, and intraoperative blood loss of the two groups of children were observed and analyzed. Results: The postoperative pain, operation time, and intraoperative blood loss scores of the children in the observation group were 4.36 ± 0.69, 0.36 ± 0.09, and 39.36 ± 1.78 respectively, which were significantly better than those of the children in the control group (P < 0.05) at 5.36 ± 0.77, 0.79 ± 0.05, and 45.36 ± 1.56, respectively. The systolic blood pressure and diastolic blood pressure of the observation group 3 minutes before surgery and 180 minutes after surgery were no different from those of the control group (P > 0.05). Conclusion: Local injection of epinephrine and lidocaine effectively relieved postoperative pain and reduced bleeding in children undergoing tonsillectomy as compared to epinephrine alone.