Objective: To understand the iodine content of drinking water in Jiuquan City, and provide a theoretical basis for effective prevention and control of iodine deficiency disorders (IDD). Methods: In 92 townships (towns, streets) of 7 counties (cities, districts) in Jiuquan City, the investigation was carried out in 2017. According to different water supply methods, that was unified centralized water supply, partial centralized water supply, and distributed water supply, stratified sampling method was used to collect water samples, and water iodine content was determined. At the same time, in the two animal husbandry counties of Subei County and Akesai County with spring water and river water as water sources, the administrative villages were taken as units, and water samples were collected to analyze the difference of iodine content in water of different water sources and different wells. According to the "Division Standard for Iodine Deficiency Disorders" (GB 16005-2009), the iodine content of drinking water < 10 μg/L could be divided into areas of iodine deficiency. Results: A total of 392 water samples were collected from 273 administrative villages in 92 townships (towns, streets) in 7 counties (cities, districts) of Jiuquan City. The median water with iodine contents was 2.6 μg/L, ranging from 0.1 to 16.6 μg/L. And 372 water samples iodine < 10 μg/L, accounted for 94.90%; 20 samples ≥10 μg/L, accounted for 5.10%. Among the 392 water samples, 33 were centralized water supply samples, 311 were partial centralized water supply, and 48 were completely distributed water supply. The median water iodine was 1.6, 2.5, and 4.3 μg/L, respectively. There was a statistically significant difference in the median water iodine between different water supply methods (Z = 24.064, P < 0.01). In Subei County and Akesai County, 108 water samples were collected. Among them, there were 64 water samples with surface water (spring water and river water) as the water source. The median water iodine content was 5.4 μg/L. And 44 water samples using ground water as the water source, the median water iodine content was 5.2 μg/L. There was no significant difference in the median iodine content between surface water and ground water (Z = -1.745, P > 0.05). There was a statistically significant difference in the median water iodine content between different depths of well water (Z = 11.113, P < 0.05), but all < 10 μg/L. Conclusions The median water iodine in different water supply modes, different water source types and different wells in Jiuquan City are < 10 μg/L, Jiuquan City is a serious iodine-deficient area in external environment. The prevention and treatment of IDD by iodized salt should be carried out for a long time.