In this paper, the effect of laser decontamination of the oxidized layer on the surface of stainless-steel metals commonly used in nuclear power plants is analyzed by numerical simulation, and the results show that decontamination of radioactive components is achieved by removing the dense oxidized layer on the surface of the material. A finite element model of laser decontamination is established by simulating the double-layer structure of the metal material and the Gaussian heat source of laser decontamination. The analytical results show that the continuous laser is not applicable to radioactive surface decontamination due to the obvious thermal accumulation effect. In order to evaluate the effectiveness and applicability of decontamination, the decontamination threshold and damage threshold indicators are proposed, and it is necessary to ensure that the substrate does not melt while considering the decontamination effect. According to the simulation study of pulsed laser decontamination, the effects of laser power and scanning speed on the ablation depth and substrate temperature are basically have a linear relationship on the ablation depth and temperature of the substrate, but the rate of temperature change increases during the enhancement of thermal cumulative effect, and the different lap rates have a greater impact on the decontamination surface morphology.