Abstract: The previous studies on the vertical penetration of structures through level ice mostly did not consider the water action, which was inconsistent with the actual application scenarios. In this paper, a numerical simulation method of ice-water-structure interaction based on structured-arbitrary Lagrange Euler (S-ALE) fluid-structure coupling method and penalty function contact algorithm is established by using LS-DYNA finite element software. Eulerian algorithm is used to describe air and water areas, Lagrangian algorithm is used to describe cylinder structure and level ice structure, and elastic-plastic strain rate model is used to characterize the mechanical properties of ice materials. Self-built test bench for vertical penetration of cylinder through level ice verified the feasibility of finite element method to calculate the interaction between structure and level ice problem. By simulating the ice-breaking process of cylinder vertical upward water breakthrough, it is compared with the ice-breaking process of cylinder vertical penetration in waterless environment. The results show that there is "water cushion effect" in the interaction between structure and level ice in water environment; The extreme value of ice breakthrough load has no significant change with the presence or absence of water; The duration of ice load when the structure breaks through level ice in water environment is obviously longer than that in waterless environment.The elastic deformation stage of level ice in water environment is longer, and the deflection change of level ice is greater than that in waterless environment. The research results of this paper provide a research basis for strength calculation and optimization design of ice-breaking structure with vertical vertical upward water breakthrough in polar ice area.