Numerical simulation of the cylindrical prefabricated fragment under explosive-driven process has been done in order to obtain more accurate prefabricated fragment calculation model and the effect of fragment deformation and fracture radius of liner on initial velocity. The calculation model on initial velocity of prefabricated fragment which considered fracture radius of liner and deformation of fragments has been established by analysis the explosive-driven process of warhead. The explosive-driven process of cylindrical prefabricated fragment has been studied by using nonlinear dynamics analysis software AUTODYN, Johnson-Cook constitutive model of dynamic and fluid-structure interaction method. The simulation results show that fracture radius increases and deformation of cylindrical prefabricated fragment reduce as the increase of thickness of liner. The calculated initial velocity of steel fragments and tungsten alloy fragments after amendment has been verified by the simulation. Result of this study has some reference for prefabricated fragment warhead design.