Numerical simulations for the jet formation behavior and its terminal effect of damaged shaped charge warhead were carried out using the AUTODYN-3D to investigate the influence of hole location, hole depth and hole diameter on jet lateral velocity and its penetration ability. Results show that any hole in the shaped charge can increase the radial velocity obviously and cause deviation of jet from the axis, which even results in jet break up into small fragments and reduced the penetration ability of jet severely. Compared to the intact shaped charge, the penetration power for damaged shaped charge with hole diameter d=0.278 times charge diameter is reduced 24% on equal conditions. It is a fact that hole location and hole diameter are the main influence factors of radial velocity for jet. With distance between the hole and the top of liner decreasing, the radial velocity of jet increases significantly and the penetration depth of the target plate decreases. The radial velocity of jet is 19.0 m·s^-1 for the hole location x=0 times of charge diameter. The radial velocity of the jet increases with the hole-diameter increasing and it can reach up to 41.1 m·s^-1 for the hole diameter d=0.278 times of charge diameter.