The　sustainable　advancement　and　low-carbon　application　of　asphalt　pavement　significantly　benefit　from　the　reutilization　of　waste　SBS　modified　asphalt　(SBSMA)　mixtures.　However,　the　high-efficiency　rejuvenation　of　aged　SBSMA　(ASBSMA)　remains　a　persistent　challenge.　In　this　study,　a　novel　reactive　rejuvenator　was　developed　using　waste　cooking　oil　(WCO)　and　methylene　diphenylene　isocyanate　(MDI)　to　restore　asphalt　components　and　reconstruct　SBS　structures　in　ASBSMA.　Temperature　Sweep,　Fourier　Transform　Infrared　(FTIR)　spectroscopy　and　Differential　Scanning　Calorimetry　(DSC)　tests　were　conducted　to　investigate　the　rejuvenation　effect　and　mechanism　of　ASBSMA.　The　results　indicate　that　the　incorporation　of　WCO　restores　the　low　temperature　performance　of　ASBSMA,　but　adversely　affects　its　high　temperature　performance.　Conversely,　the　addition　of　MDI　enhances　the　high　temperature　performance　of　ASBSMA,　but　an　excessive　dose　of　MDI　has　a　negative　impact　on　its　low　temperature　performance.　Chemical　composition　analysis　shows　that　the　rejuvenation　by　WCO　is　a　physical　dissolution　and　softening　process,　while　MDI　can　react　with　the　SBS　aged　products　to　produce　long　chain　products　with　an　amide　structure　and　reconstruct　the　cross-linked　structure　of　SBS.　Although　the　temperature　stability　of　rejuvenated　SBSMA　is　not　fully　restored　to　its　original　state,　it　shows　significant　improvement　compared　with　ASBSMA　due　to　the　reconstruction　of　SBS　structure.　This　study　effectively　clarifies　the　reactive　rejuvenation　mechanism　of　ASBSMA,　achieves　the　synergistic　restoration　of　asphalt　components　and　SBS　structure,　and　contributes　to　high-efficient　recycling　of　WCO　and　waste　asphalt　materials.