Abstract: Soil moisture sensing plays a key role in precision agriculture research. Taking dielectric soil moisture sensor as an example, the classification of soil moisture sensor and the characteristics of the sensor were systematically summarized, and the proportion of influence of prior art, soil temperature, soil moisture, soil type and soil salt on the measurement accuracy of dielectric soil moisture sensor was analyzed, and the method how to strengthen the measurement accuracy of soil moisture sensor was proposed. In order to contribute to better understanding and application of soil moisture sensors.