The numerical simulation method of the crushing process,and the mass and speed distribution characteristics of high strength steel warhead shell after explosion was studied. Taking'Exocet'missile warhead for example,the expansion and fragmentation of warhead shell driven by explosion were simulated with Smoothed Particle Hydrodynamics(SPH)algorithm.During modeling process,the explosive was plotted with Lagrange elements,the shell and end cover with SPH elements,LagrangeSPH was coupled to achieve the fragmentation of warhead shell driven by explosion. For the simulation model,different sizes of SHP particles were applied to reveal the variation laws of the amount of fragments with the size of SPH particles and the mass and speed distribution characteristics of the fragments generated by explosion. And comparing numerical simulation results with engineering analysis calculated by traditional Mott and Gurney formulas,numerical simulation with SPH particles in 0.25 cm was consistent with engineering analysis. The verified model was simulated,mass and speed distribution characteristics of the shell and bottom of the warhead after explosion were obtained,as well as mass and speed of per fragment and dispersing direction and angle of fragments for every part.