Objective To investigate and understand the iodine nutrition level and thyroid function among pregnant women in Anhui province, so as to provide a basis for scientific supplementation of iodine and thyroid function mornitoring in pregnant women. Methods From April to September in 2016, six counties(districts)were selected according to geographical location and topography, relying on maternal and child health care service centers at county level or health clinics at township level and 100 early, middle and late pregnant women each in every county were selected. Samples of edible salt, urine and blood were collected and measured. Results A total of 600 pregnant women were investigated, the median salt and urinary iodine levels were 23.0 mg/kg and 181.0μg/L, respectively, the median urinary iodine levels in pregnant women at early, middle and late stages were 211.3, 179.1 and 170.2 μg/L, respectively. Thyroid function of 547 pregnant women were measured, the mean TSH, FT₃, FT₄ were 1.8uIU/ml、5.7pmol/L and 13.8 pmol/L, the median TgAb and TPOAb were 29.3and 1.5 IU/ml, respectively. The rate of thyroid function disorders of pregnant women was 15.4%. Prevalence rates of hyperthyroidism , subclinical hyperthyroidism, hypothyroidism and subclinical hypothyroidism were 1.1%(6/547),1.8%(10/547), 5.7%(31/547)and 6.8%(37/547), respectively. The detection rates of hyperthyroidism and subclinical hyperthyroidism were statistics significance in different period of pregnancy. There were significant differences in urinary iodine ＜150 μg/L rate of hyperthyroidism and urinary iodine ≥150 μg/L rate of hyperthyroidism. Conclusion The level of iodine nutrition was suitables,as a whole but malnutrition still existed in some pregnant women of Anhui province. Subclinical hypothyroidism was the common in all thyroid function disorders of pregnant women. The detection rates of hyperthyroidism was higher in iodine nutrition deficiency.