Euler method was used in calculating the gas-liquid two-phase flow field. With the help of the user defined function (UDF) in FLUENT software, the water local collection efficiency and ice accretion on three dimensional wings were solved. The flow motion of runback water was divided along the chordwise and spanwise direction respectively during the computation procedure and the classical Messinger model was modified to be applicable to simulate three dimensional ice accretion. The analysis about three dimensional mass and heat transfer was also performed according to the modified Messinger model. Based on the traditional method of calculating heat transfer coefficient on two dimensional surfaces, an improved method was applied to compute the heat transfer coefficient on three dimensional wings. The direction of ice accretion was defined to be normal to the wing surface. The comparative results showed that the three dimensional ice accretion code developed in this paper was effective.