In this paper, we establish the cat's eye echoes model of the optical imaging system under different damage conditions and analyze the influence of the damage to CCD layers on the cat's eye echo power. Based on this, the corresponding relationship between the echo power of the cat's eye and the damage degree of the CCD was established and verified by experiments. The results show that the field intensity is the strongest in the center of cat's eye echo in the imaging optics system, and the power of the echo increases dramatically and then decrease steeply and decrease slowly. The damaged status of CCD can be judged according to this rule. This study has certain reference value for the actual situation that the degree of the damage to CCD is required to be monitored in real time in the far field.