<p>This study explores the potential of basalt fiber (BF) as an effective asphalt modifier for enhancing the properties of asphalt binder and mastic due to its remarkable strength and toughness. The research investigates the rheological and self-healing properties of asphalt mastics modified with varying BF concentrations. The dynamic shear rheometer (DSR) and bending beam rheometer (BBR) are utilized to evaluate the rheological and self-healing properties of basalt fiber-modified asphalt mastics (BFAM). At the same time, their microstructures are analyzed using a scanning electron microscope (SEM). The results reveal that incorporating BF into asphalt mastic significantly enhances its high-temperature rheological performance and deformation resistance. This improvement is attributed to the entanglement and retraction of BF. However, adding mineral powder increases the low-temperature brittleness of asphalt mastic, diminishing its crack resistance. Furthermore, the presence of aggregated BF in BFAM leads to a reduction in stress relaxation performance. At moderate temperatures, introducing BF and extended healing time enhance the self-healing properties of asphalt mastic. Conversely, mineral powder and BF impede the asphalt flow at elevated healing temperatures, slightly diminishing the self-healing properties of BFAM compared to base asphalt. The addition of BF smooths the interior of the asphalt mastic and forms a network structure, providing additional strength.</p>