The damage proceeding of charge coupled device(CCD)detector irradiated by 1.06 μm continuous laser and the weakening of the imaging capability at different damage stages are studied. Combined with damage mechanism analyzed by scanning electron microscopy (SEM) and the CCD output images at the damage stages, the reasons of the imaging quality change at different damage stages are explained. Results show that during the point damage, the microlens melts, vaporizes and loses the ability of focusing beam, which cause the incoming laser to reduce and the image gray to decrease. Besides, the vaporized microlens is adhered to the surface of encapsulated glass after cooling. These are the main reasons for the image quality reduction. During the linear damage, the deeper damage of multilayer structure by laser causes part of pixels to lose imaging capability, while the encapsulation glass is damaged due to the irradiation. So the CCD imaging ability becomes weak gradually. Combining the image clarity with morphologic detection, we built the damage assessment model to evaluate the CCD imaging capability and imaging quality at different damage stages based on existing evaluation method. By this way, the corresponding relations between damage time, damage morphology, the damage stages and the CCD imaging capability are obtained.