Abstract: Based on the data of GNSS ZTD of NMEL station of the CMONOC from November 2018 to January 2019 and the soil water content data of the Lightning River Basin Soil Moisture Detection Test Area of the Institute of Remote Sensing and Digital Earth of the Chinese Academy of Sciences, the correlation analysis between GNSS ZTD and soil water content on the monthly time scale are carried out by means of wavelet transform. The results show that GNSS ZTD is correlated with soil water content in monthly time scale, the correlation between GNSS ZTD and soil water content is significantly higher after wavelet decomposition, and the correlation between GNSS ZTD and soil water content is higher. The correlation between GNSS ZTD and soil water content is abnormal in short time, such as precipitation.