According to the mechanical effect of laser induced shock wave,the finite element simulation model of TC4 titanium alloy plate under single-pulse nanosecond laser and single-pulse femtosecond laser was established.The characteristics of the interaction of material with nanosecond laser and femtosecond laser,the relationship between layer crack and thickness of TC4 titanium alloy plate and thickness under different laser loading conditions were analyzed respectively.The simulation results show that the tensile stress under the high-energy laser loading and the deformation on the surface of the material are all related to the thickness of the material.Therefore,the degree of the layer crack is related to the thickness of the plate,which shows that the larger the thickness of TC4 titanium alloy plate is,the harder the layer crack will be.For the nanosecond laser,under the condition of the peak pressure of 6.945 GPa,the surface of the material is cracked when the thickness of the plate is 0.3 mm and 0.8 mm,the predetermined material will undergo deformation when the thickness is 1mm,and the material will be impacted and strengthened when the thickness is above 1.2 mm.For femtosecond laser,under the condition that the peak impact pressure is 41.33 GPa,the material damage is predicted when the target material thickness is 0.01 mm,deformation was predicted when the target thickness was 0.05 mm.