ObjectiveTo compare the effect of robotic thyroidectomy and endoscopic thyroidectomy on the voice function. MethodsThe clinical data of 181 patients with differentiated thyroid cancer admitted to Panzhihua Central Hospital of Sichuan Province from March 2022 to June 2023 were analyzed retrospectively. According to the operative mode, this patients were divided into two groups: the endoscope group (n=91) and the robot group (n=90). The subjective and objective acoustic indicators were compared between the two groups at 1 day before operation and 1 week, 1 month and 3 months after operation. ResultsThere were no significant difference in voice handicap index (VHI)-10 scores between the two groups at different time points before and after operation (P>0.05). There were no significant difference of VHI-10 scores between preoperative and different postoperative phases in the robot group (P>0.05). The score of VHI-10 at different postoperative phases in the endoscopic group was higher than that at 1 d before operation (P<0.05). The incidence of voice dysfunction (VHI-10 score ≥8) was 1.1% (1/90), 1.1% (1/90) and 0.0% (0/90) in the robot group, 1.1% (1/91) , 2.2% (2/91) and 0.0% (0/91) in the endoscope group at 1 week, 1 month and 3 months after operation respectively, there were no significant difference between the two groups (P>0.05). The fundamental frequency of patients in the endoscopic group was lower than that at 1 d before operation (P<0.05), and there was no significant difference between each phase after operation and at 1 d before operation of fundamental frequency in the robot group (P>0.05). The fundamental frequency of patients in the endoscopic group was lower than that in the robot group at 1 week after operation (P<0.05). The maximum phonation time of each phase after operation in the robot group was not significantly different from that at 1 d before operation (P>0.05). The maximum phonation time of 1 week after operation in the endoscopic group was shorter than that at 1 d before operation (P<0.05) and also shorter than that in the robot group (P<0.05). There were no significant difference in fundamental frequency perturbation, amplitude perturbation, harmonic noise ratio and voice disorder severity index between the two groups at different phases before and after operation (P>0.05). ConclusionCompared with endoscopic thyroidectomy, the voice function of robotic thyroidectomy via bilateral axillary breast approach is better.