A new measurement method for soil resistivity, Fast Fourier Transform(FFT) DC component method, was put forward, and corresponding power signal supply, acquisition and processing of measurement signals, measuring accuracy and data stability in the measurement were explored. First, the benefits and drawbacks of the traditional measurement methods for soil resistivity using the DC or AC power supplies were analyzed, respectively. Based on above analysis, a combination signal of DC and AC was adopted as the excitation signal of the soil to overcome the deficiency of traditional measurement methods. Then, how to isolate the DC component of the measurement signal in a frequency domain was discussed. Finally, a measurement system for soil resistivity was established. The size of the DC component and the frequency of the excitation signal were determined by a circuit experiment on the soil conductivity model, and the measurement accuracy of the system was verified. Furthermore, the stability of the measurement results was confirmed by comparing with those of traditional methods. Experimental results indicate that the error of resistivity measurement in model circuit is less than 1%, and the variance of the actual soil resistivity measurement data is 0.42, which proves that soil resistivity measurement results are reliable, accurate and stable by proposed method.