〔Abstract〕 To investigate the iodine nutrition status of children aged 8-10 in Guangming, Longhua and Yantian District of Shenzhen in 2023, and to explore the influencing factors of thyroid volume. To evaluate prevention strategies and to provide a scientific basis for the elimination of iodine deficiency disorders (IDD). Methods Urine and household salt samples were randomly collected from 580 non-boarding students aged 8-10 years for iodine content detection. Thyroid volume was measured using a fully digital ultrasound imaging system, and goiter prevalence was calculated. Results A total of 580 samples was tested. The median salt iodine concentration was 23.86 mg/kg, with 93.62% qualified iodized salt and 94.48% coverage rate. The median of urinary iodine was 265.00 μg/L, mainly distributed between 200 - <300 μg/L and ≥300 μg/L. The proportion of children with appropriate iodine was 20.86%, and the proportion of children with insufficient or excessive urinary iodine levels was 10.86% and 68.28% of the total surveyed population, respectively. The median thyroid volume was 3.27 mL, and the goiter rate was 1.72%. Multiple linear regression analysis showed that age was the risk factor for thyroid volume (β=0.328, P <0.05), while urinary iodine was the protective factor for thyroid volume (β= -4.134×10 -4, P <0.05). Conclusion The qualified iodized salt rate, median of urinary iodine, and goiter prevalence of 580 children aged 8-10 meet the elimination criteria for IDD. Age and urinary iodine are closely related to thyroid volume change. The urinary iodine level of children is generally high and requires serious attention.