Abstract: To investigate the effect of polypropylene fiber (PF) on the damage and destruction characteristics of cemented paste backfill under dynamic loads, the dynamic compressive strength of the filler specimens under single and cyclic impacts, the stress-strain curve characteristics and the macroscopic damage morphology and microstructure of the filler specimens were analyzed by preparing cemented paste backfill specimens with different ash-to-sand ratios and fiber contents (PFCPB), using split Hopkinson pressure bar (SHPB) test setup and scanning electron microscopy (SEM), macro-damage morphology and microstructure of the filled body specimens. It is found that the dynamic compressive strength of the filled body shows a positive correlation with the average strain rate. The incorporation of polypropylene fibers (PPF) can effectively improve the dynamic compressive strength of the filled body, and with the increase of the content of PPF, the dynamic compressive strength of the filled body shows an increase and then a decrease, and the optimum dosage is 0.6%. The dynamic compressive strength is increased by 25%. The results show that adding PF significantly improves the filler’s dynamic compressive strength and ductility, and the PF-containing filler is more resistant to impact under cyclic impact. In the single impact and cyclic impact experiments, with the increase of PF content, the dynamic stress-strain curve of the filling body exhibits the phenomenon of “multiple peaks”, with the peak stress gradually reduced, and the stress-strain curve being smoother in the destructive stage after the peak. Under the single impact load, the damage pattern of the filling body is mainly manifested in the shear damage. Then, tensile damage and the same approximate average strain are shown as shear damage. Under a single impact load, the damage pattern of the filling body is mainly shear damage followed by tensile damage, and under the same approximate average strain rate, the crack expansion width decreases and then increases with the increase of fiber content, and the crack width of the 0.6PFCPB specimen is the smallest. The microscopic analysis reveals that the hydration product C-S-H gel attached to the surface of the PF strengthens the adhesion force between the PF and the matrix of the filling body, which can help to slow down the expansion of the microcracks and micro-fissures and improve the mechanical properties of the filling body.