AbstractThe asphalt modifier formed by the miscibility of waste cooking oil and rubber is referred to as WRO. WRO modifiers prepared from waste tire crumb rubber (WTCR) and waste cooking oil (WCO) have the potential for solving the problems of segregation of rubber asphalt and the low recycling rate of waste cooking oil. The results of the Cole-Cole curve show that the WRO modifier can remarkably enhance the miscibility of WTCR and base asphalt. The Fourier transform infrared spectrometer (FTIR) tests proved that WTCR, WCO, and base asphalt were mainly physically miscible during the preparation of the WRO modifier and modified asphalt. In the process of preparing the WRO modifier and modified asphalt, the rubber undergoes devulcanization, conjugated double bond reduction, and oxidation reactions. The WRO modified asphalt presents great workability, storage stability, high-temperature elastic recovery, low-temperature crack resistance, and deformation recovery ability. In addition, the results of the multiple stress creep and recovery (MSCR) tests present that the WRO modified asphalt has desirable antirutting properties. The optimal preparation process of the WRO modifier preferred by orthogonal design is stirring 0.5 h at 260°C, and the mass ratio of WTCR and WCO is 6∶4.