Compared to the present diamagnetic glass used in the sensing element of optical current sensors (OCSs), the high‐sensitivity characteristics of the rare‐earth magneto‐optical glass (REMOG) can significantly improve the performance of an REMOG sensing element. The optimization objective of this study was to enhance the sensitivity of the sensing element and reduce linear birefringence. Theoretical analysis and experimental data were combined to study the practical influences of a few factors, such as the size and spatial position of the glass, the wavelength of the incident light, and the rare‐earth doping concentration, on the sensitivity of an OCS sensing element. Finally, an optimal parameter combination was obtained. The experimental results showed that the response sensitivity of the REMOG sensing element is seven times the sensitivity using diamagnetic glass.