Contact bounce is a common phenomenon in the disconnecting process of electromagnetic relays, which seriously affects the electrical contact reliability of the system. This paper introduces an optical measurement technique for characterizing the motion state of a relay reed. It delineates the kinetic energy variation and motion dynamics of the reed subsequent to relay de-energization. Furthermore, it offers a novel analytical perspective for investigating the motion behavior of the reed. By developing a characterization platform for reed rebound, leveraging the rapid response capabilities of photoelectric sensors and the high sensitivity of laser coherent imaging, the study analyzes the correlation between rebound and kinetic energy dissipation. The findings indicate that the proposed optical methodology can effectively examine the impact of spring tension on the motion state of the moving reed, thereby presenting a fresh measurement approach for assessing the reliability of the relay’s opening process.