There are different specifications for users to choose from according to their environment requirements and cost constraints. The main body of the fiberglass soil moisture/conductivity/temperature/salinity sensor is made of fiberglass, the surface is treated with a two-component epoxy resin coating, and the outer shell is made of ABS. Because the part in contact with the soil is made of non-metallic material, it is resistant to soil acid and alkaline corrosion, and the surface can withstand erosion of pH11-12 at most. By measuring the dielectric constant of the soil, it can directly and stably reflect the true moisture content of various soils. The soil moisture/conductivity/temperature/salinity sensor measures the volume percentage of soil moisture.