Abstract: In the exploitation of oil and gas in ice-covered regions, sea ice can cause strong vibration of offshore structures, result in accumulated fatigue damage of structures and threat the safety of upper pipelines and facilities and the health of staff. It is important to determine the magnitude and frequency of ice load on offshore structures in sea ice engineering. In this study, a discrete element model was developed to simulate the interaction between sea ice and vertical structures. The sea ice cover was dispersed (DEM) into spherical elements with a bonding-breaking function. The bonding strength between particles was determined through the uniaxial compression test of sea ice. The interaction between ice cover and vertical offshore structures was simulated with DEM, and the ice loads on vertical structure with various pile diameters were obtained. This investigation will benefit the rational design of new offshore structures and the fatigue life estimation of existing structures in ice-covered regions.