Objective: To investigate the application effect of dexmedetomidine in anesthesia for thyroid cancer (TC) surgery. Methods: A total of 90 patients admitted to our hospital from January 2023 to December 2023 were selected as the study subjects. The patients were divided into an observation group (given continuous intravenous infusion of dexmedetomidine during surgery) and a control group (given continuous intravenous infusion of an equal volume of sodium chloride injection during surgery) by lottery method, and the anesthesia indicators of the two groups were compared. Results: The dosages of remifentanil and propofol in the observation group were lower than those in the control group (p < 0.05); the incidence of complications in the observation group was lower than that in the control group (p < 0.05); the Visual Analogue Scale (VAS) scores of the observation group at 4 h, 12 h, 24 h, and 48 h postoperatively, both at rest and during activity, were lower than those of the control group (p < 0.05). Conclusion: During surgery for TC patients, continuous intravenous infusion of dexmedetomidine can reduce the dosage of anesthetic drugs and the incidence of anesthesia-related complications, alleviate postoperative pain, and is worthy of promotion and application.