In this paper, the sand break into highway problem in desert, which is caused by the sand flow blown by wind, is studied. The mathematical models are introduced by considering the fixed, semi-fixed and free sand desert fields based on the fluid dynamics and the sand particle dynamics. Different kinds of numerical models are made by changing the desert highway height, wind flow direction and its uniformity. The weak coupling method is used due to spatial relationships between air flow field and the sand flow field. Finally, by coupling the airflow field and sand flow field with desert highway, the numerical simulations of sand forming process on desert highway are conducted. The numerical results shown, that the wind blown sand breaks into highway easier when wind direction perpendicular highway and if the highway height higher than the range size of the sand surface the wind blown sand break into highway is more difficult.