Objective: This study aims to explore the correlation between anxiety and serum thyroid hormone levels in patients with papillary thyroid carcinoma (PTC) who underwent microwave ablation (MWA).Methods: A total of 107 PTC patients who underwent MWA were recruited. Three months after MWA, serum samples were collected from each participant to analyze their thyroid‐related hormone levels, including free T3 (FT3), free T4 (FT4), T3, T4, and thyroid‐stimulating hormone (TSH) levels. Additionally, the Self‐Rating Anxiety Scale (SAS) was used to measure anxiety levels at the same time. Linear correlation analysis was used to determine the correlation between anxiety and serum thyroid hormone levels.Results: SAS scores among the 107 PTC patients ranged from 27 to 58, with an average score of 38.19 ± 6.68. Seven patients (6.54%) met the criteria for anxiety; the mean SAS score among these patients was 51.57 ± 2.88. The remaining 100 patients (93.46%) did not meet the criteria for anxiety; the mean SAS score among these patients was 37.04 ± 5.49. Among all participants, TSH levels varied from 0.30 to 5.09, with an average of 2.08 ± 0.91. Nine participants exhibited slight fluctuations in FT3, FT4, T3, T4, and TSH levels; these hormone levels consistently remained within the normal range for the other 98 patients. Linear correlation analysis revealed a significant positive correlation between anxiety and TSH levels (p < 0.001).Conclusion: The results demonstrated a significant positive correlation between anxiety and TSH levels in patients with PTC post‐MWA, indicating that increased anxiety is associated with increased TSH levels.