Biomimetic mineralized mortar (BMM) is a green, low-carbon alternative to cement, yet its brittle failure restricts broader application. This study proposes novel fiber-reinforced biomimetic mineralized mortar (FBMM) with excellent ductility based on the coupling method of fiber reinforcement and biomimetic chemically induced calcium carbonate precipitation (BCICP). The impact of polypropylene fiber (PF) with contents of 0%, 0.2%, 0.4%, 0.6%, and 0.8% on the mechanical properties of the FBMM was investigated. Moreover, the pore structure and microscopic characteristics of the FBMM were analyzed through mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). The results demonstrate that the PF enhances the ductility of FBMM, improving residual strength and energy absorption under compression. Notably, lower PF content improves the compressive strength of biomimetic mineralized composites, while higher concentrations reduce the compressive strength. SEM images reveal that the calcium carbonate crystals, treated with polyacrylic acid (PAA), adhere well to the surface of sand particles and fibers, forming strong connections for cementing the composites. Furthermore, PF can promote more calcium carbonate to precipitate in the pores between fibers and sand particles and on the fiber surface by increasing the internal surface area of FBMM. This study investigates the synergistic effect of BCICP and fiber reinforcement, providing insights for potential practical applications of FBMM with high ductility.