The numerical analysis was conducted on the temperature and stress fields of single crystal silicon irradiated by the combined laser by the finite element method. The damage effect of the single crystal silicon which was respectively irradiated by the combined laser and continuous laser was compared, which was under the condition that the average power density of combined laser was equal to the continuous laser. The results show that combined laser is more conducive to realize thermal damage of single crystal silicon than continuous laser. The Von Mises stress, axial stress and hoop stress in single crystal silicon is higher when the model is irradiated by the combined laser than when it is under continuous lasers. The combined laser damage in monocrystalline silicon is stronger than continuous laser.