Abstract According to seismic wave data recorded by the regional digital seismic network of Ningxia regions, we get the Fourier spectrum with use of the Fourier transform, after speed records of stations geometrical diffusion correction, dielectric attenuation correction, and instrument correction using the Brune model. The Fourier spectrum is integrated to obtain the source displacement spectra in the frequency field, then the corner frequency and zero frequency. Using the radius of the epicenter, the earthquake moments and other small local earthquake source parameters are acquired using genetic algorithms. Finally, we systematically analyze the characteristics of source parameters and the relationship between the various parameters. The paper researches 210 earthquakes of Ningxia regions with ML2.0~4.9, occurring between 2008 and 2014. The results are as follows: the range of seismic moment is 1011~1015 N·m, the range of source radius is 60~766 m, the corner frequency is 1.6~222 Hz, seismic stress drop is in the range of 0.01~7.63 MPa, and apparent stress is in the range of 0.01~3.11 MPa. Some log-linear or semi-logarithmic linear relationships are shown between seismic moment, corner frequency, Richter magnitude, moment magnitude, and other source parameters.