In order to evaluate the effect of high-viscosity modifiers on asphalt properties,high speed shear method was used to prepare SBS modified asphalt,waste rubber powder modified asphalt and two SBS/rubber powder composite modified high-viscosity asphalt.The high-temperature performance,low-temperature performance and temperature-sensing performance of the high-viscosity asphalt and the road performance of the asphalt mixture were studied through three major index tests,viscosity test,high-temperature rutting test and low-temperature beam bending test.The results shown that the high-temperature performance and low-temperature performance of the four modified asphalts gradually increased with the increase of the respective modifier content.The high-viscosity asphalt mixed with 10% North American rock asphalt or 2.5% polyphosphate PPA was more stable in temperature sensitivity.The viscosity value was greatly improved,and the high-temperature performance was significantly improved.The high-viscosity asphalt and its mixture with 2.5% PPA can better resist the performance degradation under high temperature conditions,ensured the use effect and was more suitable for areas with higher temperature.High-viscosity asphalt and its mixture mixed with 10% North American rock asphalt had good performance under low temperature conditions,and recommended to be used in low temperature areas.