In order to further improve the road performance of SBS (styrene-butadiene-styrene) modified asphalt, nano-ZnO (zinc oxide nanoparticles)/SBS/asphalt composites with different nano-ZnO contents were prepared by solution casting method. Temperature scanning and frequency scanning were used to study the rheological properties of the modified bitumen, and the effect of nano-ZnO on the thermal stability of modified asphalt was analyzed by DSC (differential scanning calorimeter). By analyzing the microstructure, it was found that with the addition of nano-ZnO, the SBS gradually transformed from round particles to three-dimensional mesh structure, and the special effect of nanoparticles improved the dispersion of SBS in asphalt, and the formation of the three-dimensional mesh structure was the key to improve the performance of the asphalt application. All the results show that the modified asphalt has the best performance when the doping of nano-ZnO is 2 wt%. Meanwhile, the prepared solution can be electrostatically spun to obtain oriented asphalt fibers with a diameter of 20 µm, which may have applications in areas such as waterproof fabrics or asphalt-based carbon fibers.