Objective: To evaluate the clinical outcomes and explore the application of partial sialoadenectomy for the treatment of benign tumors in the submandibular gland (SMG). Methods: Patients with pleomorphic adenoma of the SMG who underwent surgical treatment in the Department of Oral and Maxillofacial Surgery, Peking University Shenzhen Hospital, from October 2017 to February 2021, were enrolled and assessed in the follow-up. Fifteen patients underwent partial sialoadenectomy (PS group), and 18 patients underwent total sialoadenectomy (TS group). Postoperative salivary secretion, degree of dry mouth, appearance changes of the face and neck, nerve damage, and tumor recurrence were compared between the groups. The volume of the glands on the operated and contralateral sides of the patients in the PS group, the saliva flow rate, and their correlations, were also analyzed. Results: There was no recurrence during the follow-up period. The whole saliva flow rate at rest in the PS group was higher than that in the TS group [(2.15±1.10) g/5 min vs. (1.35±0.97) g/5 min, t=2.208, P=0.035)], while the stimulated saliva flow rate was not significantly different. The objective feeling of dry mouth, evaluated by visual analogue scale (VAS) score, was more obvious in the TS group than in the PS group (Z=-2.244, P=0.025). In the PS group, the resting saliva flow rate of the SMG on the operated side was lower than that on the contralateral side of the same patient [(0.92±0.40) g/5 min vs. (1.18±0.40) g/5 min, t=-2.821, P=0.014], however, in the cases whose remaining SMG was more than 80% of the contralateral side, the saliva flow rate of both sides was not significantly different (t=-0.027, P=0.980). There was no significant difference in the saliva flow rate per unit volume of the gland on either side (t=-0.015, P=0.989), and the saliva flow rate of the operated SMG was positively correlated with the volume of the remaining gland (r=0.750, P=0.012). The VAS scores for neck deformity were not significantly different between the two groups (t=-0.997, P=0.319). No symptoms of nerve injury occurred in either group. Conclusion: Partial sialoadenectomy in the SMG can safely remove benign tumors while preserving glandular secretory function, with fewer complications and improved quality of life.