Based on the 4105A grounding resistance measuring meter, a longdistance automatic soil resistivity measuring device was developed independently to solve the problem that soil resistivity measuring instruments has to be operated manually. The measurement principles, structure, and work processes of the device are described, and the design ideas are discussed. The oneyear field experiment indicates that the system is simple and easy to use, has light weight, runs steadily, and provides quality data, being suitable for the longterm, continuous, and automatic measurement of soil resistivity.