The CMOS image sensor is widely used in aerospace, medical imaging, industrial detection, military reconnaissance, and other fields. The laser interference and damage to CMOS image sensors have also become a research hotspot in related fields at home and abroad. To investigate the impact of pulsed laser on back-illuminated CMOS image sensors, we select the Sony IMX178 back-illuminated CMOS image sensor as the target. Based on the heat conduction equation, the finite element simulation software COMSOL Multiphysics is used to compare and calculate the temperature distribution of the CMOS image sensor under the irradiation of single-pulse lasers with different parameters. The calculation results indicate that the point damage thresholds of the sensor under the effects of single-pulse lasers at 532 nm (1 ns), 1064 nm (1 ns), 532 nm (30 ps), and 1064 nm (30 ps) are respectively 61.12 mJ/cm², 75.76 mJ/cm², 31.83 mJ/cm², and 37.43 mJ/cm². Subsequently, an experimental study is conducted on the laser irradiation effects of back-illuminated CMOS image sensors. The experimental results demonstrate that the image sensor exhibits a lower damage threshold under the influence of 532 nm pulsed lasers compared to 1064 nm pulsed lasers; picosecond pulsed lasers, with higher peak power compared to nanosecond pulsed lasers, are more prone to causing point damage. The calculated point damage thresholds are highly consistent with the experimental results.