Soil moisture is an important factor affecting global climate and environment. Its spatial flow in the Earth system are crucial in global energy balance. Meanwhile, soil moisture is a key parameter controlling the exchange of water and thermal energy between land and atmosphere, directly related to atmospheric humidity, and affects the heat flux transfer from land to atmosphere. Atmospheric circulation modelling parameterized by surface parameters shows a strong feedback relationship between soil moisture and abnormal climate. Soil moisture is also an important indicator parameter in the fields of hydrology, meteorology, and agricultural science. Large-scale soil moisture monitoring and understanding are important components of agricultural study and ecological environment evaluation. At the same time, soil moisture is also the link between surface water and groundwater and an important part of the water cycle in terrestrial ecosystems. Therefore, soil moisture plays an important role in improving regional and even predicting global climate models, studying global water cycle, managing water resources, establishing watershed hydrological models, monitoring crop growth, estimating crop yield, monitoring hydrological disasters, and other related natural and ecological environment issues. Traditional monitoring of soil moisture is conducted using discrete sites or corresponding meteorological stations, but the results of this method can only represent a limited observation area and the observation process is time-consuming and laborious, unable to meet the needs of large-scale and high-efficiency soil moisture observation. At the same time, the traditional monitoring method cannot match the corresponding weather and hydrological models (0.1–10 km) in terms of spatial scale and time accuracy, so this method cannot effectively study the impact of soil moisture on environmental changes.