Objective To analyze the clinicopathological data of patients with papillary thyroid microcarcinoma (PTMC) and papillary thyroid non-microcarcinoma (non-PTMC) who received ¹³¹I therapy retrospectively, and compare the therapeutic response of the two groups of patients, so as to guide ¹³¹I therapy decisions for PTMC patients. Methods A total of 1 118 patients with papillary thyroid carcinoma (PTC) underwent ¹³¹I therapy in the Department of Nuclear Medicine, Tianjin Medical University General Hospital from January 2015 to December 2020 were enrolled. Chi-square test and Mann-Whitney U test were used to compare the differences of clinicopathological features and ¹³¹I therapy， therapeutic response between two groups. The incomplete response （IR）rate curves of the two groups were plotted by Kaplan-Meier analysis.Results The proportion of patients with multifocal, involvement of bilateral thyroid lobes in PTMC group were higher than those in non-PTMC group, and the proportion of patients with extra-thyroid extension, T4, N1b, stimulated thyroglobulin(sTg)>10 μg/L, and high risk stratified were lower than those in non-PTMC group (P<0.05). Most patients in PTMC group received remnant ablation for the first time, while more patients in non-PTMC group received adjuvant therapy and therapy for known disease (P<0.05). There was no statistically significant difference in ¹³¹I therapeutic response, the rates of excellent response(ER) and IR in two groups, and the differences in curves of IR rate between the two groups were also no statistically significance (P>0.05). Conclusions PTMC has a certain degree of invasiveness. As long as the patients were comprehensively evaluated and the standard ¹³¹I therapy was adopted, the treatment outcomes of patients with PTMC and non-PTMC were roughly the same. Therefore, the clinical value of the definition of PTMC is extremely limited in the formulation of ¹³¹I therapeutic dose regimens.