The laser-induced voltage (LIV) method has been used to characterize the oil shale directly. Explaining the generation mechanism and the response process of oil shale is expected to provide a basis for the real-time monitoring of its pyrolysis process. Here, we focused on the generation process of LIV in oil shale under the irradiation of a 532 nm laser. The influence of bias voltage and laser power on the LIV response of oil shale is studied and discussed. The LIV response strongly depends upon the laser power and exhibits an increasing trend as the laser power increases from 0.157 to 0.237 W. With the increasing temperature as a result of laser illumination, the spontaneous electric polarization results in the variation of the surface charge and the associated flow of a thermoelectric current. In addition, the current signal nonlinearly increases with an increase in the bias voltage, which has a similar form as that of the classical thermionic emission transport relationship.