Conventional optical cameras encounter numerous challenges in space target detection, including severe space radiation effects and motion blur. In contrast, the event camera, as a novel optical imaging sensor, exploits its asynchronous output to achieve high temporal resolution and a wide dynamic range, thereby exhibiting tremendous potential for space target detection. However, current research on event cameras remains limited and lacks a solid theoretical foundation. To address this gap, the present study introduces the calculation theory of blackbody radiation and incorporates key factors—such as target distance and reflective area—to establish a more precise sensitivity model for space target detection using event cameras. In addition, the critical parameters influencing sensitivity are analyzed in depth. Finally, ground based simulation experiments and nighttime star observation tests are conducted to verify both the feasibility of using event cameras for space target detection and the reliability of the developed computational model.