A kind of infiltration composite material used in desertification areas is developed. It supplies water in the way of molecular penetration, which makes the utilization of water resource to be most effective. The FTIR was used to study the changes of functional groups. The SEM and ESEM were used to analyze the composite coating’s microstructure, and its dynamic behavior under different water potential was also studied. The l-t curves and water-conducting pattern was obtained by the water-conducting experiment. Finally, the dynamic water-conducting mechanism of the composite material was studied. The results showed that the water-conducting rate had a positively correlation with the montmorillonite content. The rate can be regulated by adjusting the mass ratio of polyacrylamide and montmorillonite. The rate was increased with increasing temperature and decreasing soil moisture. The water-conducting mechanism of the composite material was closely related to the water potential gradient. The high water potential was formed at the swelling end of polyacrylamide and the low water potential was formed at the end of connected MMT particles with polyacrylamide unswollen. When the coating was at low water potential, the montmorillonite particles connected and water was conducted quickly via montmorillonite layers, whereas when the coating was at high water potential, the montmorillonite particles disconnected and water was conducted slowly via the swelled polyacrylamide structure. The water gradient was generated along the coated fiber, thus water was conducted spontaneously.