Abstract: Based on the emissive probe made of oxide cathode and the improved zero-emission limit inflection point potential technology, this paper conducts a study on the measurement of the space potential distribution between two parallel bipolar plates. The research results show that in a high vacuum environment (~10⁻⁴ Pa), the measurement results of space potential measured with the oxide cathode emissive probe can be well consistent with the theoretical results. The relative error between the two is within 0.1 V, and the measurement accuracy of space potential reaches the same level as that of the traditional tungsten emissive probe. As the oxide cathode emissive probe moved between the two bipolar plates and multiple repeated measurement verifications were carried out, the results show that the oxide cathode emissive probe maintains high precision and also has good stability during the process of space potential measurements.