To study the influence of initial parameters on the cavitation and motion characteristics of revolution bodies entering water in parallel, the realizable k-ε turbulence model, the volume of fluid (VOF) multiphase flow model, and the Schnerr and Sauer cavitation model were employed based on the finite volume method. The overlapping grid technique was used to simulate the process of water entry in parallel with different initial speeds, initial clearance distances, and cross-flow speeds. First, a numerical calculation model of high-speed water entry in parallel of revolution bodies was established, and the validity of the calculation method was verified. Then, based on this model, numerical calculations of parallel water entry with different initial parameters were performed to obtain the flow field and motion characteristics under different parameters. Finally, combined with the calculation results, the variations of the cavitation morphology and characteristic size, as well as the lateral and yaw movements of the moving bodies under different parameters were analyzed. Results show that with the increase of the initial velocity of water entry, the inner side cavitation phenomenon was more severe. With the outer polar radius and the limit length of the cavitation at the same dimensionless moment increased, the dimensionless lateral displacement and yaw angle of the revolution body were larger. As the initial clearance distance decreased, the limit length of the cavitation at the same dimensionless moment was smaller, and the dimensionless lateral displacement and yaw angle of the revolution body first increased and then decreased. Under the action of small cross-flow, the radial dimensions of the outer cavitation on the outer side of the revolution body in forward and leeward directions were basically the same with that of the single revolution body, while the length was slightly larger. With the increase of the cross-flow speed, the cavity size differences of parallel moving bodies were greater than that of single body. The radial size differences of the inner cavitation were large, where the polar radius of the inner cavitation of face-flow revolution body was greater, and with the increase of the cross-flow speed, the maximum value of the polar radius maintained around d+D/2. When the cross-flow speed was small, the two revolution bodies tended to be close to the head and far away from the tail; when the cross-flow speed was large, the two revolution bodies tended to be close to the tail and far away from the head.