Objective To perform epidemiological survey on aggregated cases of surgical site infection (SSI) after radical thyroidectomy for thyroid cancer, provide evidence for prevention and control of healthcare-associated infection(HAI). Methods Epidemiological survey was conducted on SSI patients after radical thyroidectomy for thyroid cancer in a tertiary first-class hospital between April 27, 2019 and June 7, 2019, intervention measures were given, efficacy of prevention and control was evaluated. Results There were 4 cases of SSI after radical thyroidectomy for thyroid cancer in this hospital during a short period of time, secretion cultures of surgical sites of 2 cases were methicillin-resistant Staphylococcus aureus (MRSA), and antimicrobial susceptibility profile was consistent. Surgeons, nurses and workers in the operation group were sampled (nasal cavity, forehead and hand), and the surface of environmental objects in the dressing room, treatment room and related bed units were also sampled, MRSA was isolated from the nasal cavity and hand specimens of surgeon C, susceptibility profile was consistent with MRSA cultured from the secretion of surgical site of patients. Intervention measures were given, operation qualification of doctor C was suspended, and mopirocin was used for decolonization, re-examination 10 days later, no MRSA was cultured, within one month after decolonization, no related infection cases were found, which confirmed the effectiveness of prevention and control measures. Conclusion Non-effective decolonization of MRSA can lead to aggregation of SSI, clinical departments should be encouraged to report infection events on their own initiative to reduce the risk of infection.