Abstract: The process of laser irradiated fused silica was dynamically simulated based on ANSYS. temperature field, shape of melt pool, stress evolution and distribution of residual stress were analyzed and the furthermore distressing annealing was simulated. The results show that, in the course of laser irradiation, the temperature is highest at the center of irradiation area and the temperature gradient is biggest at the edge of irradiation area. After cooling to room temperature, there is large tensile stress at the center and large compressive stress at the edge. Residual stress is significantly reduced after annealing.