The sand erosion on concrete was investigated by the gas solid two phase flow erosion experiment system. The surface microstructure damage was analyzed by scanning electron microscope(SEM). The results show that the mechanism of sand erosion damage of concrete is surface scratch failure at low erosion angles and impact indentation crushing at high erosion angles during the concrete erosion. The concrete erosion rate is increasing and then decreasing as the falling rate of sand increase. A method for evaluating the sand blown erosion of concrete is proposed, which can provide a basis for the sand protection and durability of concrete.