Abstract: Taking the application of cement and polypropylene fiber in the protection of silty clay slope as the research background, this paper explores the validity analysis of polypropylene fiber cement reinforcement material on the anti-erosion ability of silty clay slope. Based on indoor experiments, the research investigated the effects of varying cement and fiber content on the shear strength of silty clay. A slope erosion model experiment was conducted based on predetermined experimental ratios. The results indicate a positive correlation between cement content and the shear strength of silty clay. Additionally, polypropylene fiber was found to further improve the cohesion of the reinforced soil. The slope ratio initially enhances and then diminishes the anti-erosion effect on the soil. Compared to unreinforced slopes, the erosion resistance of the strengthened side slope is significantly improved. Scanning electron microscopy (SEM) analyses revealed that the improved erosion resistance of the reinforced soil results from the hydration of cement and the dispersed arrangement of polypropylene fibers, which promote interparticle cohesion and form a robust structure, thereby enhancing the soil's impermeability. The research results offer novel engineering application insights for protecting slopes against erosion.