Under different active temperature, the thermo-voltage of four kinds of typical minerals, such as magnetite, arsenopyrite, pyrite, and chalcopyrite, were tested by thermoelectricity equipment BHTE-06. All the minerals showed that the absolute value of the thermo-voltage rose with active temperature increasing. Based on the theory of thermoelectricity and the analysis of genetic environment of natural minerals, the authors assume that the semiconductor minerals widely exist in crust and most of them have the thermoelectric property. Therefore, the in-depth study of thermoelectric effects of natural semiconductor minerals is of revelatory significance for understanding the general mechanism of abnormal change of geoelectric field before an earthquake.