Based on the Bernoulli equation and the boundary layer theory, the drag reduction characteristics of supercavity bodies in the supercavity state are analyzed compared with those in the fully wetted state and the partially cavitating state, and the effects of the nose cone half angle, the length-diameter ratio and the tail shape on the drag are discussed. The simulation results show that the drag reduction effect of supercavity vehicle is obvious. Under the constraint of the same length-diameter ratio, the drag increase effect of reducing the length is more obvious than that of reducing the diameter, and the drag reduction effect of the frustum of a cone tail is weaker than that of the cylinder tail with the increase of the cavity.