Objective：This study aims to investigate the effects of intraoperative neuromonitoring（IONM）on postoperative voice outcomes of by differentiated thyroid cancer（DTC）. Methods：We assessed patients with DTC underwent thyroid surgery in the First Affiliated Hospital of Sun Yat-sen University from September 2018 to March 2019. According to whether IONM was used or not，the patients were divided into IONM group and non-IONM group. Clinicopathological characteristics and voice outcomes between IONM and non-IONM patients with DTC were compared using propensity score matching（PSM）. Results：In the whole population and the subgroup of lymph node dissection in the prevention center，there was no statistical difference between the two groups in the total score of the voice handicap index-10（VHI-10）and the voice field of the thyroid cancer specific quality of life（THYCA-QoL）questionnaire 1 and 6 months after surgery（P>0.05）. In the subgroup of approaching or invading the posterior capsule，the median（quartile）THYCA- QoL voice score in the IONM group at 1 month and 6 months after surgery was 0.00（0.00，0.00）lower than in the non-IONM group 0.00 （0.00，33.33），（P=0.034）. The score of THYCA-QoL in the IONM group was 5.73 lower than that in the non-IONM group 15.66（P= 0.029）. There was no statistical difference in the VHI-10 questionnaire. Conclusion：IONM has no significant effect on subjective phonation disorder in patients with DTC and subgroup patients with preventive central lymphadenectomy. However，it can significantly improve the subjective voice abnormalities of patients in the approaching or invading the posterior capsule subgroup after surgery.