Abstract: Electrical monitoring technology is widely applied in mines with high risk of water inrush because of its high sensitivity to the change of coal resistivity. However, due to the complex working environment of the two lanes of the underground working face, the ground conditions between the different field source emission monitoring electrodes are quite different and change with time, so it is difficult to provide stable field source signals in the whole monitoring cycle. A negative feedback type intrinsically safe electrical monitoring device based on STM32F407 is designed. The device can adapt to adjust the access resistance between different transmitting electrodes and has dual reliable intrinsically safe protection circuit. The maximum power stable transmission of the next source signal is realized under the inherent safety restriction condition, and the field source energy is maximized to load into the target monitoring geological body to obtain the strongest possible field source response signal, improve the data acquisition quality of the electrical monitoring system and improve the accuracy of the inversion interpretation.