The sand cover is the main form of sand disaster for the desert highway induced by the wind-blown-sand flow over the highway. As a kind of two-phase flow of air and sand, it is necessary to study the physical principle and the mode of its migration. The Smoothing Particle Hydrodynamic (SPH) method is adopted to simulate the movement of the wind-blown-sand flow. A two dimensional model of the sand cover for desert highway with embankment is built with SPH method. The numerical simulations are carried for different embankment height to investigate the sand cover distribution on the road surface of desert highway. The results show that the migration of sand with wind blow can be well simulated using SPH method and the embankment height is an important factor for controlling sand cover disaster of desert highway.