To address the issues concerning the temperature field distribution and ablation depth during laser cleaning of oxide layers on Q195 steel, a finite element heat transfer model for nanosecond pulsed laser cleaning with a Gaussian heat source was established. By simulating the laser-material interaction, the effects of pulse width, average power, and spot overlap rate on the temperature field of the oxide layer, ablation morphology, and heat-affected zone were analyzed. The results indicate that at a laser power of 30 W and a frequency of 100 kHz, the ablation crater diameter increases with the pulse width. When the pulse width is 200 ns, both the diameter and depth of the ablation crater exhibit an approximately linear growth with increasing average power. This study provides a theoretical basis for optimizing the laser cleaning parameters for oxide layers on Q195 steel