This paper aimed to investigate the reinforcement effects of basalt fiber, polyester fiber, and lignin fiber on semi-flexible pavement materials and study their applicability in different structural layers. The optimum bitumen-aggregate ratio under different fiber dosages was determined through the leakage test and dispersion test, and the optimum fiber dosage was determined through the Marshall test. The fiber reinforcement effect was evaluated through the Marshall test, rutting test, low-temperature bending test, freeze-thaw splitting test, and splitting fatigue test. A three-dimensional finite element model was established by using ABAQUS software to analyze the mechanical response of semi-flexible materials in different structural layers. The results show that basalt fiber, polyester fiber, and lignin fiber all improve the road performance of semi-flexible materials, with basalt fiber demonstrating a significant reinforcement effect in semi-flexible pavement materials. The semi-flexible materials have the best application effect in the upper and middle layers, which can improve the durability of pavement structures, effectively delay pavement fatigue damage, and enhance rut resistance, and they are particularly suitable for heavy-duty road sections and high-temperature environments.