Using AUTODYN-2D non-kinetic software, a research has been carried out on the discretization process of continuous media with damage cracking due to the impact load of polysilicon. By Using SPH method, a simulation test has been carried out of the impact process of different width tungsten alloy hammers on polycrystalline silicon target at different positions and different impact speeds, followed by an analysis of the crack generation and propagation modes under different impact loads, thus obtaining the relationship between impact velocity, shape and size of impact surface, impact location and particle size of fragments. The simulation results show that when the impact velocity is less than 25 m/s, the crack point approaches the central axis with increasing speed. When the impact velocity is greater than 25 m/s, the length of the main crack expansion will no longer increase, while the density of the bifurcation crack will increase. When the impact velocity is greater than 40 m/s, the crack propagation remains basically unchanged. When the width of the hammer head is 20 mm and the impact velocity is 40 m/s, the impact method of hitting the center of polysilicon can effectively control the broken size between 5~90 mm to greatly reduce polysilicon waste.