Pointing at the main problems existing in the utilization of point scale in soil moisture measurement, a linear scale measurement method was put forward and a sensor system of soil profile moisture information measurement was designed based on standing wave ratio method. With the help of a high frequency electromagnetic field simulation software HFSS and vector network analyzer, electric field distribution and impedance characteristics of sensor ring probe were analyzed and studied to determine the adaptation and sensitive areas of the ring probe. Two kinds of soil in different textures were taken as experimental samples, the output and the corresponding measured value of soil moisture sensors were executed polynomial fitting, and the results showed that the determination coefficient was above 0.99 and the steady and dynamic performances of sensors could satisfy the requirement of soil profile moisture measurement. The experiments of multi-layer moisture through the soil column showed the system could meet the soil profile moisture real-time measurements demand in linear scale and it had high measurement precision and stability. Meanwhile, the system was satisfied with needs of practical application and it had high application promotion value.