Based on the Rayleigh-Plesset equation and the Vof multiphase flow model, a numerical simulation method of the underwater projectile motion process was established according to the flow field characteristics of the underwater projectile at different angles of attack. Under the same initial velocity, the effects of projectile motion at different angles of attack on the cavity shape, flow field evolution and force characteristics in the process of motion are compared and analyzed. The results show that the larger the angle of attack is, the worse the cavitation effect is, and the larger the lift and drag are, which will seriously affect the underwater trajectory stability of the projectile.