Abstract: Based on the process of liquid composite molding(LCM), it existed unsaturated regional experiment phenomenon, can be understood flow in dual-scale porous media gradually. Some scholars proposed to use sink model to study of unsaturated flow in dual-scale porous media. The features of dual-scale porous media in the LCM by volume averaging method were described, and dual-scale LCM mass conservation equation which contained sink term was obtained, and the finite element method was used to solve differential equation numerically. Through a specific example, under the condition of constant pressure, the pressure distribution in the different periods in dual-scale porous media is calculated. The change process of unsaturated regional near resin flow front is got. The different injection pressures are used to simulate and compare. Compared with single-scale porous media, dual-scale porous media can reflect unsaturated regional phenomenon in practical filling process better.