Objective: To explore the clinical characteristics of patients with pituitary thyrotropin-secreting adenoma and evaluate the effect of preoperative short-acting octreotide treatment on hyperthyroidism. Methods: A retrospective analysis was performed in 40 patients with pituitary thyrotropin adenoma diagnosed in Beijing Tiantan Hospital from January 2008 to January 2018. The general data, laboratory examinations and imaging findings were reviewed and analyzed. The clinical effect of preoperative octreotide on hyperthyroidism was evaluated. Results: The age of onset year of the 40 patients (male: female = 24∶16) was (30.5±5.1) years. Among them, 35 patients (87.5%) were with macroadenoma. The most common symptoms were thyroid hypermetabolism syndrome, followed by headache, dizziness, visual field damage and hypogonadism. The thyroid function of 30 patients (75%) recovered to normal within 3-5 days after the octreotide treatment. The total effective rate of the octreotide was 90.0%. The level of free thyroxine (FT4) before treatment in patients with more than 10 times of effective cumulative dose was significantly higher than that in patients with less than 10 doses. Conclusions: Thyroid hypermetabolism syndrome and pituitary occupying effect are the most common clinical manifestations of thyrotropin-secreting adenoma. Preoperative octreotide treatment can effectively control hyperthyroidism. The level of FT4 is a crucial factor affecting the efficacy of octreotide.