The increasing use of CMOS technology has made it essential to improve its resistance to laser damage in the field of optoelectronic countermeasures. This research examines the characteristics and mechanisms of damage to CMOS caused by 1064 nm continuous lasers and 532 nm pulsed lasers. The damage progresses through four stages: lens damage, point damage, line damage, and stress damage. Results show that continuous laser exposure leads to gradual expansion of the damaged area over time, while narrow-pulse multi-pulse lasers cause more severe damage to CMOS. Lens and point damage are mainly caused by thermal ablation, which reduces the CMOS light source’s focusing efficiency and damages the MOS structure. Line and stress damage result from a combination of thermal ablation and thermal stress. Damage to the metal wiring layer can cause entire rows or columns of pixels to fail, while the insulation layer may rupture due to thermal stress expansion, ultimately leading to CMOS function failure during imaging.