Abstract: In view of the present steel-structure coating surface has long been eroded by sandstorm in the central and western region of Inner Mongolia,the sand flow injection test method was used to simulate sandstorm erosion wear on the steel-structure coating. The influence of sandstorm erosion mechanic parameters of erosion rate was studied. The erosion tribological mechanism of steel-structure coating was discussed. The variation law of the steel-structure coating's impact friction coefficient was analyzed.Results show that the erosion rate of the coating rises exponentially with the erosion speed,and the growth index n is about 2.39-2.43; the erosion rate is up to maximum when the erosion-angle is 45°,and the erosion rate is up to minimum when the erosion-angle is 90°,and the erosion rate at low erosion angle is greater than that at high erosion angle. The friction coefficient of coating is about 0.37-0.42,and the coating's wear Taber index is 81.9 × 10^-3mg/r,so the wear resistance of the coating is poor. The tribological damage mechanism of coating is that the dominant damage comes from the micro cutting effect at angle. Impact friction coefficient and erosion rate along with the change of the erosion angle is not consistent. Low erosion angle or squeezing the chisel cut effect at high erosion angle causes the primary damage to the coating,and the secondary damage to the coating comes from the expanding micro cracks of the coating surface which causes cracking and peeling. The impact friction coefficient of the coating shows large discreteness,and it decreases with increasing.