Abstract: Femtosecond laser can ablate explosives to produce high temperature and high pressure plasma within a very short time. So it can be used to precisely process explosive components and safely dispose of used ammunition. A deep understanding of the laws of femtosecond laser ablation of explosives is the basis for the development of new technologies for femtosecond laser processing of explosives. Based on the nonlinear finite element method, the detonation calculation model of the femtosecond laser ablation explosive process was established. The numerical simulations of the femtosecond laser ablation of LX-17 and LX-10 were carried out. The pressure distribution laws in plasma and explosive at different femtosecond laser energies were obtained. The computational results indicate that the initial pressure of the ablation product plasma and the explosive near laser action zone is very high during the femtosecond laser ablation, but owing to the small ablation zone, the shock wave pressure in explosives decreases rapidly and no detonation occurs.