To study the effect of hydrothermal coupling aging on the performance of rubber modified asphalt,this article simulated thermal aging and hydrothermal coupling aging tests and investigated the effect of different aging environments on the high-temperature and low-temperature performance of asphalt from macroscopic and microscopic levels through conventional index tests,dynamic shear rheology tests,and gel chromatography tests,as well as the effect of different aging environments on the interfacial properties through low-temperature adhesion tests of asphalt and aggregates.The results show that the effects of hydrothermal coupling aging on the ductility and softening point of rubber modified asphalt are more significant than those of thermal aging.The rutting factor,phase angle,and critical temperature of rubber modified asphalt increase with the increase in aging time,and the temperature sensitivity decreases,meaning that the high-temperature performance of the rubber improves.However,the changes in the hydrothermal coupling aging environment are more significant.Both thermal aging and hydrothermal coupling aging lead to the degradation of the interfacial properties of asphalt aggregates,but hydrothermal coupling aging has a greater influence.The macromolecular content CLMS (%) and dispersity D-value both increase with increasing aging time,but hydrothermal coupling aging increases the degree of growth in the early stage.D-value and CLMS (%) have a good correlation with softening points and ductility.