To address the existing mortar materials’ low tensile strength, poor ductility, and high susceptibility to cracking and failure in drainage network spray repairs, this study introduces polyvinyl alcohol (PVA) fibers as a reinforcing agent in a new cement-based composite material. The research explored how cement type, silicon powder content, fiber content, and water-cement ratio affect mortar’s working performances. Results demonstrate that cementitious with ordinary Portland cement and 10% silicon powder, the mortar mixture had good fluidity and the specimens demonstrated high strength. Building on this mixture ratio, the study further examined the effects of fiber volume content and water-cement ratio on the mortar's mechanical properties. At a fiber content of 2.5% and a water-cement ratio of 0.31, the mortar showed high strength, achieving compressive and flexural strengths of 100.2 MPa and 16.3 MPa, respectively, after 28 days. During tensile testing, the mortar specimens exhibited multiple cracks and high ductility, with an ultimate tensile strength of 5.0 MPa and a strain of 2.3%. The bonding strength was 2.2 MPa, and the impermeability pressure exceeded 1.5 MPa. On-site spray tests revealed that at 28 days, the specimens’ compressive strength was 88.4 MPa, with an ultimate tensile strength of 4.9 MPa and a strain of 2.1%. This suggests that while the spray test led to a reduction in the mortar's mechanical properties, it still retained high strength and ductility. This study aims to serve as a reference for developing high-strength, high-ductility cement-based composite materials for pipeline repair sprays.