Abstract: Thyrotoxicosis during pregnancy mainly includes gestational transient thyrotoxicosis (GTT) and Graves’ disease (GD). It is important to distinguish between GTT and GD because these two diseases are treated differently. At present, gold standard is lacking for the differential diagnosis of two diseases. Detection of thyroid-related antibodies combined with medical history and clinical manifestations are the most common differential methods. In recent years, researchers at home and abroad have proposed alternative valuable differential indexes, such as thyroid-related antibody, superior thyroid artery peak systolic velocity of color Doppler ultrasound of the thyroid, thyroid hormone and human chorionic gonadotropin, etc. In this article, the differential diagnosis significance of each index was summarized, aiming to provide better reference for the differential diagnosis of GTT in pregnancy and GD.