Abstract: In order to investigate the drag characteristics of high speed projectile in the states of supercavitation shape, four projectile models were designed, whose structure parameters were in accordance with a typical projectile structure with disk cavitator. Experimental studies of the high speed projectiles in underwater shipping were performed and the average drag coefficients of projectiles were obtained through data processing. The influences of the cavitator diameter, the aspect ratio of projectile andcavitation number on the drag characteristics of projectile were analyzed. Finally, drag coefficients of projectiles were numerical studied with Fluent6.2. On the base of experimental data and numerical simulation, the supercavitation drag reducible characteristics were explored. The results show that the drag coefficient increases with the cavitator parameter. Smaller drag coefficient of the projectile can be obtained by increasing the slenderness ratio. The supercavitation drag reduction ratio of the high speed projectile is above 95% in supercavitation shape.