To improve the accuracy of particle method in simulating the mechanical properties of ice, especially the plastic deformation characteristics of ice in the failure process, this paper proposes an elastoplastic constitutive model of ice bending failure based on the peridynamic theory of meshless particle method. Peridynamics is a newly proposed non-local theory, which is formulated in an integral form and can be applied to predict failures without extra assumptions. In addition, peridynamics is effective in deformed bodies, even in discontinuous objects. First, on the basis of Von-Mise criterion, the elastoplastic constitutive model of ice was established according to the relationship of incremental plastic strain and incremental plastic stress. Then, the application method of boundary conditions and the criterion of ice failure were analyzed. Next, the numerical calculation method of the constitutive model in FORTRAN was introduced. Lastly, the four-point ice bending process was simulated by using the ordinary state-based peridynamics method, and the force curve over time was predicted. The simulation results were compared with experimental results. Results show that ice failure process, crack propagation mode, and force curve predicted by the numerical model were in good agreement with the experimental results. Therefore, the numerical model established in this paper can be applied to the prediction of elastoplastic bending failure process of ice. The proposed constitutive model improves the basic numerical strategy for simulating the actual ice breaking process of ships sailing in horizontal ice.