Abstract: In February 2018, the former China Food and Drug Administration (CFDA) ordered a number of changes to the guidelines for methimidazole tablets, including a change to "ban the drug for lactating women" which was far from clinical practice. Considering the particularity of anti-thyroid drugs (ATDs) for women in lactation, we searched PubMed and other databases and combed the clinical evidence and guidelines for ATDs for women in lactation. A large amount of clinical evidence suggests that ATDs by women during lactation has no obvious effect on the thyroid function, physical intelligence growth and development of the infant. The maximum safe dose was 30 mg·d^-1 of methimidazole (MMI) and 300 mg·d^-1 of propylthiouracil (PTU). MMI is the first choice of ATD for women in lactation, while PTU is recommended only in the case of hyperthyroidism or severe hyperthyroidism and allergy to MMI.