Abstract: In order to study the interaction of Laguerre-Gaussian beam and fused quartz, the method of simulation calculation was adopted to study the temperature and thermal stress of the fused quartz irradiated by 3 modes of Laguerre-Gaussian beam (TEM₀₀, TEM₀₁, TEM₁₀). The simulation data were obtained. The results show that spatial distribution of laser intensity affects temperature distribution and stress distribution of the materials. The accumulation effect of temperature is obvious. After continuous laser pulse action, the material temperature continues to rise. The focus area is over 1900℃. The temperature gradient leads to thermal stress. The local thermal stress is close to 50MPa. The simulation results provide the useful reference for the processing of fused silica.