The optical thin films play a very important role in the regulation of the light field in the laser system, but they are also easily damaged by the cumulative effect of high-energy-density pulsed laser irradiation. The damage such as melting and cracking occurs. In this paper, Ta2O5/SiO2 double-layer antireflection coating (183.33 nm/249.3 nm) is designed. Based on the thermodynamic principle, the temperature field and stress field model of the laser-induced Ta2O5/SiO2 double-layer film are constructed. The temperature and stress of the film were simulated. The results show that when the laser irradiates the Ta2O5/SiO2 double-layer anti-reflection coating, the coating layer is thermally damaged and thermal stress is generated, the thermal stress changes abruptly, and the coating layer is thermally induced stress damage. The damage mechanism has important guiding significance.