An approach based on the Eulerian two-phase flow theory to numerically simulate ice accretions on an aircraft wing is developed. The air flowfield is obtained through Euler flow computation. The water droplets flowfield is solved through proposing a permeable wall to simulate the droplets impingement. The droplets collection efficiency is calculated according to the droplets velocity and apparent density distribution. The thermodynamic model of ice accretion is based on the classical Messinger model and an integral boundary layer method is employed to account for roughness effect in calculating the convective heat transfer coefficient. The ice shape is built with the assumption that ice grows in the direction normal to the airfoil/wing surface. The ice accretions on a NACA0012 airfoil and a GLC-305 wing model under different icing conditions are evaluated and the comparison between the predicted results and experimental data indicates that the simulation approach developed in this paper is feasible and effective.