We combined large eddy simulation (LES) with a thermodynamic slab ice model to simulate and study the sea ice motion and frazil ice dynamics in the ocean mixed layer in the Arctic winter. To show the accurate representation of leads in models, fluxes distributed laterally beneath leads and sea ice need to be parameterized. The 3-D LES model, which is developed from a 2-D turbulence model, is used to model the convection of beneath leads and sea ice. The experiments were then achived by combining the LES model with the ice model. The concentration of frazil ice was modeled using the Omstedt and Svensson model. The ice crystal radius and growth rates were assumed to be constant and the temperature and salinity changes with depth were taken into account. Salinity distribution and frazil ice concentration were influenced by ice motion, and variations in ocean salinity during freezing and thawing were also investigated. Entrained flow caused by the movement of sea ice has a significant influence on the eddy. Sea ice roughness is also important in the formation of the eddy current, and the values of the ice crystal rise velocity and the ice concentration source term coefficient influence frazil ice dynamics. The effects of sea ice thermodynamic dissipation on the sea is more remarkable, affecting the heat transfer to the atmosphere. The brine rejected during ice crystal formation and dilution of seawater are other important mechanisms of marine cyclical shocks.