To understand the distribution of traditional Chinese medicine(TCM) constitutional types and TCM syndrome in Hashimoto's thyroiditis(HT) patients and investigate the correlation of disease-constitution-syndrome.Methods:A cross-sectional survey method was used on 460 patients with HT for TCM constitutional type and syndrome distribution investigation.Combined with the thyroxine function indexes，SPSS 26.0 software was employed for correlation analysis.Results:The most frequently appearing TCM constitutional types in HT patients were yang deficiency，qi stagnation，qi deficiency，phlegm dampness，yin deficiency，dampness-heat，special，and blood stasis.The most frequently appearing TCM syndromes were spleen deficiency and phlegm congealment，liver stagnation and phlegm coagulation，qi and yin deficiency，phlegm stasis and coagulation，spleen and kidney yang deficiency，as well as yin deficiency with effulgent fire.HT patients' thyroxine function was correlated with the 4 constitutions of neutral，yin deficiency，yang deficiency，qi stagnation，and yin deficiency，as well as 2 syndromes of yin deficiency with effulgent fire，and spleen deficiency and phlegm coagulation(P<0.05).Additionally，TCM syndrome was correlated with qi deficiency，yin deficiency，yang deficiency，phlegm dampness，dampness-heat，and qi stagnation(P<0.05)，with yang deficiency as a risk factor for HT with hypothyroidism(P<0.05).Conclusion:Among HT patients，yang deficiency，qi depression，and qi deficiency are the most common TCM constitutional types，while spleen deficiency and phlegm coagulation are the most common symptoms.There is a correlation between HT “disease-constitution-syndrome”，in which constitutional types affect the syndrome classification and prognosis development.The “constitution differentiation-disease differentiation-syndrome differentiation” provides a novel perspective for the diagnosis and treatment of HT.