Five sizes of Salix psammophila checkerboard sand barriers (1×0.5,1×1,1×2, 2×2 and 2×3 m² in size; 15, 25 and 35 cm in height) in Mu Us sand land were set and the processes of sand flow near dune surface were analyzed in order to determine the protective benefits of the sand barriers. Results showed that the component of fine powder on dune surface increased obviously by Salix psammophila checkerboard. Compared with bare dune, the sand flux relative-intensity of checkerboard was reduced obviously. Combined with the local natural conditions and economic factors, the 2 m×2 m Salix psammophila checkerboard sand barrier is suitable for windbreak and desertification control in Mu Us sand land.