Abstract: In recent decades, the incidence rate of thyroid cancer has been increasing significantly in many countries including China, especially papillary thyroid cancer, and women tend to have a higher incidence rate. Many residents mistakenly believe that "salt iodization" is the cause of the high incidence rate of thyroid cancer, which has an impact on the prevention and treatment of iodine deficiency in China. This article reviews the epidemiological characteristics and pathogenesis of thyroid cancer, especially the association between thyroid cancer and iodine nutrition. The results show that although the incidence rate of thyroid cancer is high, the mortality rate remains relatively stable, and both iodine deficiency and excessive iodine may be risk factors for thyroid cancer, but there is no evidence that "salt iodization" can cause thyroid cancer.