The experiment that visible CCD was damaged by CW laser, 40 kHz laser and 5 kHz laser was carried out individually. Similar injury phenomenon was observed, which includes point damage, linear damage and complete damage. And the resistance between driving electrodes and substrate was measured corresponding to every injury state. Stereoscan photographs of the three damaged CCD slug were obtained to analyze the micromorphology of damaged positions. Through analysis, the causes of three different injury phenomenon were extracted and the different mechanism of CW laser, 40 kHz laser, 5 kHz laser irradiating CCD was discussed. The conclusion is that superficial injury causes point damage; light leakage and cutting out of driving electrodes lead to linear damage; and the injury of insulating barrier results in complete damage. Furthermore, fusion is the main process of CW laser irradiation; carburation and ablation are major causes of 40 kHz laser injuring CCD; and the factors of 5 kHz laser injuring CCD consist of carburation, ablation, eroding and recoil strength.