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 (P0.05). 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.