Abstract: Spontaneous electric field is a kind of geophysical field with clear physical meaning and variation mechanism, which is used in various domains like mineral resource prospecting, hydrogeologic survey and earthquake monitoring. Based on preliminary study on omni-directional spontaneous electric field observation methods, this paper focuses on the analysis and discussion of spontaneous electric field observation techniques, including a kind of Pb-PbCl₂ non-polarized electrode, multi-channel high-precision data measurement, network control and data communication, and technical realization of portable design and environmental temperature adaptability. Finally, it presents a brief introduction and discussion on the observation system and data of the spontaneous electric field at Jinghai seismic station in Tianjin Municipality. The results show that ① omni-directional spontaneous electric field variation with time could be captured by this method; ② measurement of electric field and its temporal change in 360° azimuthal range could be carried out by using the spontaneous electric field observation techniques, which have high observation precision, strong ability of anti-interference and strong environmental adaptability; ③ multi-directional changes of spontaneous electric field, which were possibly related to seasonal changes of the surrounding water, were recorded by the test observation system of Jinghai seismic station.