With the increase in traffic volume and vehicle load, higher demands are put forward on the quality of expressway in high-temperature areas. In order to prepare high-performance modified asphalt, the base asphalt is chemically modified with amine-functionalized micro-nano-SiO2 (d=10 μm and 20 nm). Using azobisisobutyronitrile as an initiator, Maleic anhydride (MAH) reacted with base asphalt to form activated asphalt (MQL). Then the modified asphalt (PEI-SiO2-MQL) was obtained by polyethyleneimine-modified SiO2 (PEI-SiO2) and MQL under melt blending condition. The surface morphology of the asphalt characterized by SEM reveals better dispersion of PEI-SiO2 in asphalt in comparison to that in pure SiO2. The FTIR analysis shows that there are both chemical reactions and physical interactions between PEI-SiO2 and asphalt. The results of softening point, rheology and aging tests demonstrate improvements in high-temperature stability, anti-rutting and anti-aging performance of PEI-SiO2-MQL. Asphalt with amine surface-modified micro-nano-SiO2 modification has great potential as road materials on expressway in high-temperature areas.