Abstract: The effect of reactive elastomeric terpolymer (RET) on properties of matrix asphalt and styrene butadiene styrene block copolymer(SBS) modified asphalt was discussed by viscosity test and dynamic shear rheometer test. The surface topography characteristics of SBS modified asphalt and RET-SBS modified asphalt were analyzed by atomic force microscopy(AFM). Through wheel tracking test, bending test at low temperature, bending fatigue test and accelerated loaded test, the technical performance of RET modified asphalt mixture was evaluated. Finally, the fatigue properties of different RET modified asphalt mixture were analyzed by Weibull distribution under different failure probabilities. The results show that RET can significantly increase the viscosity and rutting resistance factor of asphalt, which obviously improves the rheological properties of asphalt at high temperature; RET-SBS modified asphalt can improve viscous component of asphalt; Compared with SBS modified asphalt, the surface roughness of RET-SBS modified asphalt increases significantly; RET has a significant effect on improving stability at high temperature; RET-SBS modified asphalt can improve crack resistance at low temperature, the fatigue properties and long-term stability at high temperature of asphalt mixtures.