In order to meet the requirements of the development of new water entry weapons such as barrier-breaking projectiles and fly-assisted torpedoes, the numerical simulation of the shock response of projectiles during water entry is carried out, and the effects of warhead shape, water entry initial velocity and water entry angle on velocity attenuation and overload response are compared and analyzed. The simulation results show that the flat-headed projectile has the fastest attenuation speed, followed by the cone-headed projectile, and the round-headed projectile has the slowest attenuation and the smallest overload peak, its head structure is most conducive to the stability of water movement; the greater the initial velocity of entry, the faster the velocity decay, the load on the projectile increases more obviously; when the round-headed projectile enters the water at 60 degrees, the speed attenuation is relatively slow in the early stage, and the overload peak is relatively low. The research results can provide the theoretical reference for the design of the projectile and the selection of the initial state of entering the water.