In view of the current standard analysis method of iodide in groundwater is only a single spectrophotometric method, and there are some shortcomings such as harsh reaction conditions, low sensitivity and low accuracy, it is very important to establish an efficient and accurate method of iodide test for monitoring high-iodine groundwater in coastal areas. In this study, by referring to the gas chromatographic analysis method of National food safety standard: Testing methods for drinking natural mineral water (GB 8538–2022), the sample concentration was realized while the operation steps were simplified by optimizing the sample pretreatment steps, the linear concentration range of the standard curve was expanded, and an analytical method suitable for the measurement of iodine content in groundwater in areas with high iodine content was established. The data showed that the correlation coefficient of the standard curve of iodide was greater than 0.999 in the range of 0.0 to 1.0 mg/L. The limit of detection was 0.0002 mg/L, RSD<5.0%, and the recoveries were 86.1%~114%. The method has the advantages of high sensitivity, good repeatability, high accuracy and wide range of test concentration, which can reduce the matrix difference and error caused by sample dilution, and is suitable for the analysis and test of iodide in groundwater in high iodine area.