Abstract: Ocean electric field signals are widely used in the fields of geological tectonics, water target detection, physical ocean, and the analysis of ocean physical characteristics. It is of great scientific value to collect the ocean electric field signals, while the ocean electric field is measured using ocean electric field sensors. In recent years, perovskite-type composite oxides have become a research hot spot as new materials. Among these composite oxides, SmNiO3 is the one that possesses some unique properties including metal-insulator phase transition, strong stability in seawater, and high sensitivity to low-frequency electric field signals. Therefore, it is expected to become a new type of electrode materials in ocean electric field sensors. Domestic and foreign researchers have carried out some studies on SmNiO3, which mainly focus on the electrical properties (especially the metal-insulator phase transition and optical properties) and preparation process of SmNiO3. This paper systematically reviews the above research contents and preliminarily explores the feasibility of applying SmNiO3 in marine electric field sensors.