Abstract <p>Cislunar space, as a strategically significant domain for humanity’s future survival and development, has become a new battleground for deep space exploration activities among leading spacefaring nations. Driven by the growing demands for deep space exploration missions, the monitoring and early warning of cislunar space debris have increasingly become a priority. Precise orbit determination (POD) of cislunar space targets provides essential support for debris surveillance. Against this backdrop, this study proposes a ground/space/lunar integrated optical observation model, implemented through SPOT (Small Body and Planets Precise Orbit Determination Toolkit)—a software platform independently developed by Wuhan University’s Planetary Geodesy Team. We conducted numerical simulations for POD of targets at Earth–Moon libration points L1, L4, and L5. The results demonstrate that the orbit determination accuracy using only ground-based observations is on the order of several hundred meters. Space-based observations can serve as a valuable supplement to ground-based data, providing a modest improvement in accuracy. However, the addition of lunar-based observations significantly enhances the orbit determination accuracy, reducing position errors and uncertainties to the order of tens of meters. Furthermore, variations in the noise level of lunar-based observations have a stronger impact on orbit determination accuracy than space-based observations. Finally, comparative experiments verify the necessity of solving the solar radiation pressure coefficient Cr for improving orbit determination accuracy. These findings highlight the tremendous potential of lunar-based optical observations in achieving high-precision orbit determination for cislunar space targets and provide valuable insights for future advancements in deep-space situational awareness and autonomous navigation.</p>