Abstract: Thyroid cancer is one of the most common endocrine cancer. ¹³¹I treatment is one of the important treatment methods in differentiated thyroid cancer(DTC) postoperative, which plays a key role in reducing the recurrence rate of patients and improving the quality of life. ¹³¹I treatment is classified as ionizing radiation. The reproductive system is highly radiosensitivity, and its exposed to ¹³¹I from the blood, bladder urine, and intestines may cause transient damage to the ovaries or testes, which is manifested mainly by increased serum follicle-stimulating hormone levels, premature ovarian failure, decreased sperm count and viability. and decreased levels of anti-müllerian hormone. Existing clinical studies are still controversial about whether ¹³¹I trerapy of DTC increases the risk of secondary tumors in the reproductive system remains controversial. Therefore, the radiation effect of ¹³¹I therapy of DTC on reproductive system radiation has attracted wide attention.