The collapse and formation process of quasi-spherical explosively formed projectile(EFP)was simulated by nonlinear dynamic software AUTODYN.Effects of structure parameters of liner outer curvature radius(R₂)and liner thickness(h)on the velocity and length/diameter ratio of EFP were studied.Results show that as the increasing of outer curvature radius and liner thickness,velocity and length/diameter ratio of EFP decrease.The relationship between outer curvature radius and liner thickness of the quasi-spherical EFP is obtained.X flash radiographs of EFP with structure parameters h=0.136Dk and R₂=0.76Dk are obtained.The results of numerical simulation are well agreement with X flash radiographs.