To investigate the ultrasound imaging characteristics of patients with refractory hyperthyroidism, and to analyze its correlation with related serological indicators. Methods 156 patients with refractory hyperthyroidism (observation group) and 121 healthy individuals (control group) in our hospital from January 2016 to January 2018 were enrolled. All the selected subjects received laboratory examination and color Doppler ultrasound. Various indexes were compared between groups, including ultrasound imaging characteristics, serological indicators total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), free thyroxine (FT4), and thyroid stimulating hormone (TSH). The correlation between imaging characteristics and serological parameters was analyzed by Pearson correlation analysis. Results The thyroid volume, maximum flow rate, and tube diameter of the observation group were significantly higher than those of the control group (P<0.05), and the blood flow resistance index of the observation group was slightly larger than that of the control group, with no significant difference (P>0.05); The levels of serum FT3, FT4, TT3, and TT4 in the observation group were significantly higher than those in the control group (P<0.05), and TSH levels were significantly lower than those in the control group (P<0.05); Pearson correlation analysis showed that TSH was negatively correlated with thyroid volume, maximum blood flow velocity, and tube diameter (r<0, P<0.05); FT3, FT4, TT3, and TT4 were positively correlated with thyroid volume, maximum blood flow velocity, and tube diameter (r>0, P<0.05); Conclusion Ultrasound examination of thyroid volume, maximum blood flow velocity and tube diameter of patients with refractory hyperthyroidism can reflect the severity of refractory hyperthyroidism, thus providing reliable reference for diagnosis, treatment and monitoring of refractory hyperthyroidism.