To improve the comprehensive road performance of in-situ recycled asphalt mixtures, this study investigates the impact of the amount of rejuvenator on the performance of recycled asphalt based on rheological performance parameters such as rutting factor, creep stiffness, creep rate, and critical temperature difference．It proposes a method for determining the quality ratio of rejuvenator to reclaimed asphalt based on the relationship between continuous high-temperature grades and continuous low-temperature grades．This method balances the high-temperature and low-temperature performance of asphalt to define the quality ratio of rejuvenator to reclaimed asphalt．Based on the determined quality ratio, asphalt mixtures are prepared, and the high-temperature and low-temperature performance of these mixtures is compared with those determined by the penetration method for the same quality ratio of rejuvenator to reclaimed asphalt．The results indicate that as the quality ratio of rejuvenator to reclaimed asphalt increases, the rutting factor of recycled asphalt measured by dynamic shear rheology gradually decreases, the creep stiffness measured by bending beam rheology decreases, the creep rate increases, and flexibility improves．The quality ratio of rejuvenator to reclaimed asphalt determined based on continuous high-temperature and low-temperature grades results in a slight decrease in the high-temperature performance of the recycled asphalt mixture, but the water-saturated Marshall residual stability increases by 9. 4%, the freeze-thaw splitting tensile strength ratio increases by 7.9%, and the bending failure strain of the small beam increases by 5.5%, effectively balancing the high-temperature and low-temperature performance of the recycled asphalt mixture．