The polyformaldehyde (POM)/polypropylene (PP) blends with different POM contents (5%, 10% and 15%) were prepared by melt blending method, and the POM/PP blend fibers were prepared by a two-step process of "melt spinning and stretching". The effects of POM content on the physical properties of POM/PP blends and the surface morphology, mechanical properties and matrix bonding properties of the blend fibers were studied by rotational rheometer, scanning electron microscope and fiber tensile force meter. The results show that the addition of POM improves the melt processability and thermal stability of the blends, as well as the surface roughness, creep resistance and matrix bonding of the fibers. When the POM mass fraction is 10%, the fracture strength of the fiber reaches 3.32 cN/dtex, and the matrix bonding strength in epoxy resin is 68.9 kPa, making it a high-performance reinforcing material.