To study the characteristics of impact loads on the tails of supercavitating projectiles undergoing tail-slaps,a simple model for fluid region based on the Logvinovich’s Principle was presented,and the FSI method was employed.The effects of initial disturbance angular velocity,mass of projectiles,position of centroid and rigidity of projectiles on the impact loads of tail-slaps were investigated by simulations.The results showed that the greater the projectile’s mass and initial angular velocity and the smaller the elastic modulus,the greater the impact loads.The impact times increase with the increasing of initial angular velocity,however the impact times decrease,while the impact durations increase,with the mass increase and the center of mass moving back.As result,tail-slap forces which could destroy the structure and the moving stability of the projectiles can be lessened by smaller initial angular velocity,lower density,and larger elastic modulus of the bodies.