Abstract: According to the characteristics of the sand environment in the middle and west regions of Inner Mongolia, the erosion resistance of polypropylene (PP) fiber/cement composites with different PP fiber contents in the sand environment was studied by using the simulated wind sand environment erosion experimental system. The micro-morphology of PP fiber/cement composites after erosion was observed by using SEM, and the erosion mechanism was explored. The results show that the erosion rates of the PP fiber/cement composites with different PP fiber contents are as follows: Cement mortar PP fiber/cement composite with mass ratio of PP fiber to cementitious is 1.5% PP fiber/cement composite with mass ratio of PP fiber to cementitious is 0.5%. Within a certain erosion time range, the evolution characteristics of erosion damage have changed significantly. The erosion rates of PP fiber/cement composites with different fiber contents increase with the erosion angle, and different peaks appear when the erosion angle is 90°, which accords with the characteristics of brittle materials. By analyzing the surface contact stress in erosion process and combined with the micro morphology after erosion, it is pointed out that the appropriate amount of PP fiber will improve the compactness and toughness of the PP fiber/cement composites. However, the addition of excessive PP fiber will cause uneven dispersion and reduce the compactness and erosion resistance of the mortar. The PP fiber/cement composites with excellent erosion resistance can be produced by matching the content of PP fiber reasonably.