Objective To analyze clinical features of reoperation patients with differentiated thyroid cancer, and to explore reason, surgical pattern and therapeutic effectiveness of reoperation. Method The clinical data of 80 patients with differentiated thyroid cancer underwent reoperation from January 2012 to June 2016 in Peking Union Medical College Hospital were analyzed retrospectively. Results ① Eighty (5.37%) patients with differentiated thyroid cancer underwent reoperation were identified from a total of 1 491 patients with thyroid cancer in our treatment team. Twenty-seven cases were males, 53 cases were females. The male to female ratio was 1∶1.96. The age was (44±13) years with a range from 14 to 66 years. The median time between reoperation and the first operation was 16.8 months with a range from 8 days to 17 years. ② Thirteen cases underwent reoperation because of uncertain frozen sections, and the reoperation style was residual lobectomy and selective lymph node dissection. Sixty-seven cases underwent reoperation because of local recurrence or metastasis, 15 of them accepted residual lobectomy and selective lymph node dissection while the other 52 accepted selective lymph node dissection. ③ The rate of residual in thyroid cancer confirmed by postoperative pathology was 18.8% (15/80). The rate of cervical lymph node metastasis was 63.8% (51/80). The temporary laryngeal recurrent nerve injury occured in 6 cases, the temporary hypocalcemia occured in 9 cases, and the lymphorrhagia occured in 2 cases. ④ The hospitalization time was (6.50±0.97) d with a range from 3 to10 d, the time of drainage tube remove was (2.41 ±0.95) d with a range from 2 to 7 d. Seventy-three cases were followed up from 3 to 58 months with (32±18) months, 4 of them underwent operation once again because of local recurrence, no distant metastasis or death happened. ⑤ The proportion of male patients in reoperation patients was significantly higher than that of the first operation patients (P<0.05). The proportion of patients aged <45 years, the average hospitalization time, the average time of drainage tube remove, and the postoperative complications rate had no significant differences between the patients with the first operation and the patients with reoperation (P>0.05). Conclusions For reoperation patients, proportion of male patients is higher. Reoperation is proper treatment for patients with residual lobe or local recurrence or metastasis for differentiated thyroid cancer. Serious complications could be avoided by suitable surgical pattern and careful dissection during operation. Residual lobectomy and selective lymph node dissection are suggested for reoperation.