Abstract: The floating speed of large submarine escape capsules is comparatively large,and once it comes out of the water surface,the water-reentry process may induce great impact and pose threat to the crew members. In order to study the effects of submarine escape capsule shaping parameters on its movement safety,this paper presents a theoretical model of the floating process and the water-reentry movement of the multi-scale escape capsule. The FLUENT and ANSYS/ LS - DYNA are applied to simulate the overall process. Research results show that the emerging velocity of the capsule as well as the reentry impact decrease with the growth in the diameter of escape capsules,which in turn raises the security level of submarine escape capsules.